Great video explaining these reactions! My professor tends to lose me by going into too much detail and forgetting that we are not all professionals in OCHEM. This video gives me exactly what I need to know about each reaction in a simplified manner! Thank you!
So many professors forget that the reason they have students is that it is their job to teach chemistry to those who don't yet know it! I'm glad my videos are able to fill in where your professor is unable to
leah, i want to show you my gratitude for helping me passing my orgo 1 class. my prof did nothing but showing up on time for the lecture lol. you truly are godsend!
This was so great! It eliminated the need to review all the videos (that I have already watched several times while learning the concepts), in a compact, "remember these" concepts way. Perfect for day before finals review!
she is doing great, some of us cant afford to pay for you tube videos, for example me, am very poor from the most poor country. so stop influencing her that we should pay for her videos.
This was ABSOLUTELY amazing! Someone in my organic chem group sent this video to the gc and I was happy to watch it! With the situation of COVID my class has been stuck online and it is really hard to understand or ask for help... So, this video really helped out. Thank you!
Thank you so much, our professor started this chapter on the last week of class. By watching this video before every class, it allowed me to get more familiar with the material and gradually add the mechanisms behind the results as they were discussed in class.
I know that this is an older video, and I don't know if this channel is really active anymore, but this video is honestly going to be my saving grace for the exam I have tomorrow. Thanks, Leah!!
You are the best. I'm on the chapter of Reactions to Alkenes and it's a huge chapter to read. We have the powerpoint slides but the professor just goes through each slide which makes it hard to understand. Your video pretty much summed up most reactions that we reviewed in class. But now, I have a better understanding.
Thank you so much Leah, You are amazing. Your videos help a lot to understand the difficult concepts of Organic chemistry. I am watching all of them and this video is a summary for many chapters in my textbook. Thanks again and God bless you, wish you all the best Leah!
My Organic professor is terrible. Reads straight out of the book on an overhead and never works out any problems. Also makes you feel stupid if you ask for help. THANK YOU SO MUCH for these helpful videos. It's hard to teach yourself organic chem out of a textbook.
Couldn’t believe I just found ur video this is very clear and helpful! I’ve been struggling with the products of these reactions now you’ve cleared my doubts thank you so much
4:20- In another video, she explained that this is due to the polar bond formed between the H and O which gives the H a partial positive charge and negates it
I don't have a video dedicated to the nomenclature of molecules with chiral centers. However, you will find these topics addressed in my free Chirality and Stereochemistry series where I walk you through how to identify R and S configurations for chiral molecules. Watch the series at Leah4sci.com/Chirality
***** Thanks. I know I failed though, but now that i'm aware of your channel since few days ago, I will actually be able to learn the concepts next term. =)
Thank you! I‘d be interested in hints at why and how a step can go wrong and the risks involved with specific reactions. I understand that is more than is asked in most chemistry education but it is very relevant in daily practice. I really like your colour scheme, we both share a trait 😉
I'm sure it's relevant in daily practice, but alas it is not something I can help with. I'm strictly a pen & paper chemistry tutor, I haven't been in lab for over a decade
everything was purely explained and thnc for clarifying some tricky things. But mem i only have ONE PROBLEM "HOW DO YOU SEE IF YOU AN HYDRIDE SHIFT"??????
Glad I helped clear things up for you. Regarding your questions, a hydride shift can occur in organic chemistry reactions that involve a carbocation intermediate. If such a rearrangement will place the carbocation on a more substituted carbon, then the hydride shift is highly favorable because of its ability to stabilize the intermediate. For more, visit leah4sci.com/hydride-shift-mechanism/
Very good but only one question.... In the hydrohalogenation example, isn't the Cl going to go on the C that has the less H, being a Markovnikov reaction? Why does the Cl go on a C that has no pi bonds?
Listen to my explanation in the video one more time. For this example, there is a hydride shift that allows the carbocation to be formed on the more substituted, tertiary carbon. For more on the mechanism of a hydride shift like this one, I invite you to watch the following: ruclips.net/video/cSW9LDxtuoA/видео.html
How is a pi bond breaking into two bonds to connect to the oxygen at 9:32? Also why on some reactions are we shifting to the tertiary carbon and on others we are not?
I have a tutorial on this Alkene Epoxidation reaction where I break down the mechanism and exactly how these electrons rearrange themselves. Read more at Leah4sci.com/epoxidation As for the tertiary carbon, if the reaction mechanism proceeds by a carbocation intermediate, then the reaction should choose to rearrange to create the most stable intermediate possible. However, if the reaction does NOT proceed by a carbocation intermediate, then we will not see that rearrangement.
Actually, no. The formation of the halonium ion intermediate prevents the possibility of a carbocation rearrangement. For more on this reaction, watch my video at ruclips.net/video/S-2CaHDhMfI/видео.html
Hi! I was wondering why there is a hydride shift in the hydrohalogenation, but not any of the others shown given that true same alkene is being used in each mechanism. Doesn’t each alkene reaction exhibit a carbocation intermediate, and if so, why do the other examples not go through a hydride shift?
I'm sorry, but I don't offer tutoring over social media. For help with questions like this and more, I recommend joining the organic chemistry study hall. Details: leah4sci.com/join or contact me through my website leah4sci.com/contact/ You can also view my free Alkene Reactions video series and cheat sheet at Leah4sci.com/alkene
How do I know if a reaction will do an anti markovnikov addition or a markovinkov addition? Is it just purely memorizing which reaction does what or is there some trick
To understand why any given reaction produces a Markovnikov or anti-Markovnikov product, you must understand something about the reaction mechanism itself. Determining the favored product of the reaction is really all about identifying the reaction intermediate. In short, Markovnikov reactions usually have highly stable carbocation intermediates, while anti-Markovnikov reactions do not show a carbocation intermediate. For more on this, visit my tutorial at leah4sci.com/markovnikov
They can definitely be represented using dashes and wedges! I did not show the stereochemistry here in this video, but the product of the halogenation does have two chiral centers. I would put one on a dash and one on a wedge to show the anti addition.
I love your videos but I seem to need some background to understand this one because I could not be more lost. What is the prequel to this video? I was following the playlist/series..?
Think of this video as a short summary of all of the other alkene reactions presented in the series. As such, I would watch this video either first (as a preview of what’s to come) or watch it last (as a quick review of everything). For the entire series, in correct order, visit my website at leah4sci.com/alkene-reactions
Im not sure if you realized but you contradicted yourself for the halohydrin. you mentioned that the halogen goes to the less substituted (markovnikov because more H bonds) but then you said that this is a markovnikov reaction because the solvent without the H adds to the more substituted carbon which is the opposite of markovnikov.
Thanks for watching and for your comment! I do not believe I contradicted myself. Halohydrin formation is a Markovnikov reaction because the nucleophile (in this case, the polar protic solvent) adds to the more substituted carbon. It is the solvent, not the halogen, that adds last in the reaction mechanism. For the complete breakdown of the reaction mechanism, visit leah4sci.com/halohydrin-formation/
From a stereochemical perspective, oxymercuration is an anti addition. This has to do with the formation of the mercurinium ion as an intermediate. The nucleophile cannot attack from the same side as the mercury because of steric hindrance. If you’d like to further break down any statements from your textbook, I’d love to do so in my Organic Chemistry Study Hall. For more information, go to studyhall.leah4sci.com/join
at 4:07 why does it look like both bromines are added to the same side? If the reaction is supposed to proceed with anti stereochemistry doesn't that mean both Br atoms come from opposite faces of the double bond? You only form the trans isomer right?
while you are absolutely correct this version of the product does not show stereochemistry as denoted by the lines rather than dashes and wedges. It does however state 'anti' to remind you that this is an anti addition
Your videos are just mind blowing and amazing. Can you please make videos providing cheat sheets for chapters like carbonyl compound, carboxylic acids, phenols and ethers?
To understand, we need to look more closely at the mechanism of the halohydrin formation. There is no carbocation intermediate formed, but rather a halonium ion which stabilizes the positive charge and prevents rearrangement. Check out more on this mechanism by visiting leah4sci.com/halohydrin-formation-alkene-reaction-mechanism/
Hello leah can you check back the oxidative cleavage with hot KMnO4 in your cheat sheet..? the 2nd products in the cheat sheet gives formic acid (HCOOH) but in your video 11:57 it gives CO2
I'm guessing the CO2 as the 2nd product is correct. After cleavage the unsubstituted carbon should become CO2, monosubstituted become COOH and disubstituted become ketone
Yes, you are absolutely right! Thank you for pointing this out. The correct second product of the oxidative cleavage reaction with KMnO4 would be CO2. A terminal carbon on an alkene will be fully oxidized. Again, thank you! We will correct the alkenes cheat sheet on our site.
hii, thanks for the video, it was really helpful. but im still a bit confused at the Halohydrin process, according to what u said it should be following mark's rules, but if thats the case, why does the H-shift from tert-C to sec-C doesnt happen to form tert-Carbionium ion, since it would be more stable, and the end product would then be 4bromo 2methyl 2ol butan ?
im currently thinking its because of the intermediate, where both C of the double form form a bond with Br, which gives them the positive partial charge, and the H-shift doesnt like the positive charge so much, but the OH- ion does, thats why the OH-Ion jump right into the sec-C, but wouldnt that make it an anti marks product?
The intermediate is the key here! Rather than having any sort of hydride shift, what we see in this mechanism is the formation of a halonium intermediate where the halogen (in this case, bromine) forms a bridged intermediate across the former pi bond. But even in this bridged intermediate, we see a preference for the partial positive charge to fall on the more substituted position. Therefore, the alcohol comes in and attaches to that more substituted carbocation (the Markovnikov position) in the second step. For more on the mechanism of the halohydrin formation, make sure to see my video at Leah4sci.com/halohydrin
In this case there is no carbocation intermediate. The nucleophile (H2O) attacks the delta positive carbon on the bromonium. Because there's no true carbocation, no rearrangement
There's no 'free' carbocation in this reaction. Instead it's a partially positive carbon held in place by the bromonium. OH is attracted to the partially positive carbon and IN attacking, breaks the carbon-bromine bond. Without a free carbocation there is no shift
quick question, so these are just different ways/methods in breaking an alkene? because if so, these different ways can also be used with organic synthesis reactions? btw, your videos have helped me so much! so thanks for posting these great videos :)
10 years later this video is still helping OChem students, you're awesome
WOOHOO! Happy to still be helping a decade later!
Great video explaining these reactions! My professor tends to lose me by going into too much detail and forgetting that we are not all professionals in OCHEM. This video gives me exactly what I need to know about each reaction in a simplified manner! Thank you!
So many professors forget that the reason they have students is that it is their job to teach chemistry to those who don't yet know it! I'm glad my videos are able to fill in where your professor is unable to
leah, i want to show you my gratitude for helping me passing my orgo 1 class. my prof did nothing but showing up on time for the lecture lol. you truly are godsend!
Aww, I'm so happy to help! Unfortunately not all professors know how to teach, so filling in the gaps is needed. Glad to help!
This was so great! It eliminated the need to review all the videos (that I have already watched several times while learning the concepts), in a compact, "remember these" concepts way. Perfect for day before finals review!
that was exactly the point! so glad to help
Make sure you try the practice quiz once you feel confident with all the reactions
Honestly never once liked these overview videos but this one is an exception. Amazing explanation and cheat sheet. Truly helpful!
I'm honored that this video is an exception for you. So glad you gave it a chance and found it helpful.
Life changing so far. Thank you so much! I'm surprised you're providing videos of this quality for free.
she is doing great, some of us cant afford to pay for you tube videos, for example me, am very poor from the most poor country. so stop influencing her that we should pay for her videos.
@@mcmillanbanda6817 yabva....this comment though....tell them
@@mcmillanbanda6817 what country are you from
You're very welcome!
This was ABSOLUTELY amazing! Someone in my organic chem group sent this video to the gc and I was happy to watch it! With the situation of COVID my class has been stuck online and it is really hard to understand or ask for help... So, this video really helped out. Thank you!
Glad it was helpful!
Thank you so much, our professor started this chapter on the last week of class. By watching this video before every class, it allowed me to get more familiar with the material and gradually add the mechanisms behind the results as they were discussed in class.
wow! that's good to know! Thanks for following along. Please make sure to subscribe. You're welcome. :)
I know that this is an older video, and I don't know if this channel is really active anymore, but this video is honestly going to be my saving grace for the exam I have tomorrow. Thanks, Leah!!
Yes, the channel is still active, I just get behind on my replies sometimes. So glad to help you with your exam!
You are the best. I'm on the chapter of Reactions to Alkenes and it's a huge chapter to read. We have the powerpoint slides but the professor just goes through each slide which makes it hard to understand. Your video pretty much summed up most reactions that we reviewed in class. But now, I have a better understanding.
That is so nice to hear! Thank you for the feedback. Glad to be of help :)
Thank you so much Leah, You are amazing. Your videos help a lot to understand the difficult concepts of Organic chemistry. I am watching all of them and this video is a summary for many chapters in my textbook. Thanks again and God bless you, wish you all the best Leah!
You are very welcome! I'm glad the videos help :)
i cant believe this video is 9 years old... doing gods work thank you so much
Time flies! I'm glad it can still help people.
holy moly... I finally found a video where someone is explaining the reaction in a digestable manner. all is well now.
So happy to help you understand!
Just want to express my appreciation to leah4sci, these videos really help me a lot 😊 you're the best 🤟
Happy to hear that!
im not kidding when I say you have helped me understand SOO much I cant thank you enough. You make things so much simpler!
Happy to help!
This video makes me wish you were my Ochem professor. It's much easier to focus on your explanations rather than my professor's explanations.
Sometimes it just takes a different perspective. Glad to help!
My Organic professor is terrible. Reads straight out of the book on an overhead and never works out any problems. Also makes you feel stupid if you ask for help. THANK YOU SO MUCH for these helpful videos. It's hard to teach yourself organic chem out of a textbook.
I'm sorry you are having a less than positive experience with your professor!
I'm glad the videos are helping!
Thank god you exist, thank you so much!, you explain it so much better than my lecturer.
You're welcome, happy to clear things up for you!
Your vids are some rare gems !
Aww, thanks for your kind words! I'm so glad you like them!
Thanks for sharing this video! I do appreciate the commitment you have given to creating each video.
My pleasure! Thank you for the kind words
You’re my favorite channel for ochem help, thanks a lot
Wow, thanks! Happy to help!
now u are my new organic teacher... thank u
LOL! Too funny.
You are very welcome!
Кратак, јасан, прегледан, сликовит, занимљив и свеобухватан подсетник за реакције алкана. Свака част.👍
Thanks so much for your kind words!
So far this been the hardest topic in orgo1 for me thank you very much
You're very welcome, glad I could help!
Thank you so much Leah!! I'm reviewing for the OAT and these videos for a quick recognition of the reactions is SO helpful!
You're so welcome!
:)
Couldn’t believe I just found ur video this is very clear and helpful! I’ve been struggling with the products of these reactions now you’ve cleared my doubts thank you so much
You're so welcome!
Love you Leah thank you so much. You cannot imagine how wonderful your talent is and how helpful you are.
Aww, thanks! You are so welcome!
I’m so worried about my exam but you sum everything up very clearly. Thank you.
Happy to help! Fingers crossed for your upcoming exam!
4:20- In another video, she explained that this is due to the polar bond formed between the H and O which gives the H a partial positive charge and negates it
Yes, for more on the mechanism of the Halohydrin Formation, make sure to visit Leah4sci.com/Halohydrin.
Thanks for watching!
thank you for this!! I wish I found it sooner but you're such a lifesaver Leah!
You're welcome! I'm glad you found my resources!
Hi, I really liked the video. Congratulations for your work!
Thank you very much, glad you like it!
Thank you Leah for this awesome video and providing the cheat sheet! This is so helpful!
You're very welcome!
thanks you are way better than my teacher, thanks for this video
Happy to help! You're welcome.
You are simply the best m'am .Do you have any lecture on dash wedge nomenclature of organic compounds,I'd look forward seeing it.Thank you very much 🖤
I don't have a video dedicated to the nomenclature of molecules with chiral centers. However, you will find these topics addressed in my free Chirality and Stereochemistry series where I walk you through how to identify R and S configurations for chiral molecules. Watch the series at Leah4sci.com/Chirality
Out of all of organic chem 1, this was the stuff that I struggled with most. This video will definitelly help me alot on my final tomorrow =)
***** Thanks. I know I failed though, but now that i'm aware of your channel since few days ago, I will actually be able to learn the concepts next term. =)
Glad this helped, sorry to hear that you still failed the class
@@Leah4sci I'm currently working in the field I studied several years for, so it all ended well :)
Leah, you are great.
awww! Thank you :)
great thank you so much i wish i could find this sooner and save time on understanding other materials! thanks again this saved me
Better late than never though, right? Hope it helped and you're very welcome
Thank you! I‘d be interested in hints at why and how a step can go wrong and the risks involved with specific reactions. I understand that is more than is asked in most chemistry education but it is very relevant in daily practice.
I really like your colour scheme, we both share a trait 😉
I'm sure it's relevant in daily practice, but alas it is not something I can help with. I'm strictly a pen & paper chemistry tutor, I haven't been in lab for over a decade
Your videos are a lifesaver thank you so much!!❤
You're so welcome, glad it helped!
thanks for making organic chem simple
Aww, you're so very welcome, that's my goal!
i love you. thank you so much. this was so cut and dry and to the point
I'm glad you like it!
Just the videos I have been looking for!!!🔥🔥🔥😁
Yay!!! So glad you found them!
What a. Lecture!!! Don't stop we want more lecture🙌🙌🙌
Thanks!
Leah, I truly thank you for your videos! You are the O. chem Goddess!!!
Lol you are very welcome!
third orgo 1 test on this stuff on tuesday, and this was so helpful leah! your videos have gotten me through organic 1!
me right now lol my exam is tuesday and im watching videos for orgo 1 for my third exam
@@suhamoten2060 Me now! Except Coronavirus is giving us an advantage of taking it online now....
honored to be able to help
Thank you! God bless you!
You're very welcome
U r awesome mam😍 ... U teach the way as my teacher taught ne in class... Thanks
It's my pleasure :)
everything was purely explained and thnc for clarifying some tricky things. But mem i only have ONE PROBLEM "HOW DO YOU SEE IF YOU AN HYDRIDE SHIFT"??????
Glad I helped clear things up for you. Regarding your questions, a hydride shift can occur in organic chemistry reactions that involve a carbocation intermediate. If such a rearrangement will place the carbocation on a more substituted carbon, then the hydride shift is highly favorable because of its ability to stabilize the intermediate. For more, visit leah4sci.com/hydride-shift-mechanism/
My exam is tomorrow and all I have to say is THANK YOU
you're so welcome! How did your exam turn out?
Very good but only one question.... In the hydrohalogenation example, isn't the Cl going to go on the C that has the less H, being a Markovnikov reaction? Why does the Cl go on a C that has no pi bonds?
Listen to my explanation in the video one more time. For this example, there is a hydride shift that allows the carbocation to be formed on the more substituted, tertiary carbon. For more on the mechanism of a hydride shift like this one, I invite you to watch the following: ruclips.net/video/cSW9LDxtuoA/видео.html
god bless u this is exactly what i needed
Glad I could help!
your lectures are awesome..😄
Glad you like them!
How is a pi bond breaking into two bonds to connect to the oxygen at 9:32? Also why on some reactions are we shifting to the tertiary carbon and on others we are not?
I have a tutorial on this Alkene Epoxidation reaction where I break down the mechanism and exactly how these electrons rearrange themselves. Read more at Leah4sci.com/epoxidation
As for the tertiary carbon, if the reaction mechanism proceeds by a carbocation intermediate, then the reaction should choose to rearrange to create the most stable intermediate possible. However, if the reaction does NOT proceed by a carbocation intermediate, then we will not see that rearrangement.
Really wonderful summary!
Thanks!
This was an awesome recap ! thank you
You're welcome!
The video is still very hot despite the fact that it was uploaded 7 years ago. It seems like one uploaded yesterday, thanks 🙏
All thanks to my students who keep watching and making my stuff relevant! You're so welcome. :)
MAAM U ARE CRAZY GOOD LOVE U LOADSSSS
Aww thanks so much, so glad I'm able to help
Great video, simple and detailed thanks
You're welcome!
thanks a ton for these review videos.Helped a lot!
You're welcome, happy to help!
Thank you so much Leah😫😫🙏🙏
You're very welcome!
this was actually so helpful
glad I could help!
Thank you for your work!
You're very welcome!
Thank you Leah. Your videos are very helpful
You're so very welcome, happy to help!
In the halohydrogenation 4:32 would there be a carbocation shift towards the tertiary carbon so that OH would be on the more carbon
Actually, no. The formation of the halonium ion intermediate prevents the possibility of a carbocation rearrangement. For more on this reaction, watch my video at ruclips.net/video/S-2CaHDhMfI/видео.html
Very good video! straight to the point
Glad you liked it!
Leah can you plz explain the syn and anti addition by using cis and trans or E and Z isomers?1 I don't know how to show these effects!
I'm planning to do a video on this soon
Amazing! God bless you Leah!
Thank you!!
wow i get it now i was confused since first semester now its clear thanks a lot
You are welcome. I'm glad it helped
great understanding with simple concepts
Glad you liked it!
Thank you, Leah! This video is very helpful.
You're welcome Bethany! Glad to help! :)
Great! It helped a lot! Would like more of such videos..
+Leah Fisch You're welcome.. Do you have any dedicated video on Syn and Anti addition?
Can you please make one.. It would really be helpful!
Glad to help and yes
U teach really very good 👌
Thanks!
Hi! I was wondering why there is a hydride shift in the hydrohalogenation, but not any of the others shown given that true same alkene is being used in each mechanism. Doesn’t each alkene reaction exhibit a carbocation intermediate, and if so, why do the other examples not go through a hydride shift?
I'm sorry, but I don't offer tutoring over social media. For help with questions like this and more, I recommend joining the organic chemistry study hall. Details: leah4sci.com/join or contact me through my website leah4sci.com/contact/
You can also view my free Alkene Reactions video series and cheat sheet at Leah4sci.com/alkene
Great video, thank you!
Glad it helped! You're welcome.
That is a great work. it really helped me
Glad it helped!
during Halohydrin i thought a methal shift would occur to place the OH on the more stable carbocation?
at which point in the video?
How do I know if a reaction will do an anti markovnikov addition or a markovinkov addition? Is it just purely memorizing which reaction does what or is there some trick
To understand why any given reaction produces a Markovnikov or anti-Markovnikov product, you must understand something about the reaction mechanism itself. Determining the favored product of the reaction is really all about identifying the reaction intermediate. In short, Markovnikov reactions usually have highly stable carbocation intermediates, while anti-Markovnikov reactions do not show a carbocation intermediate. For more on this, visit my tutorial at leah4sci.com/markovnikov
@@Leah4sci thank you, jus wondering do u cover content for organic 2
Thank you for all your help !
You're welcome, happy to help!
fantastic video and cheat sheet. thank you.
Glad you found it helpful
at 3:43 you cant put them on dashes or wedges because of chirality?
They can definitely be represented using dashes and wedges! I did not show the stereochemistry here in this video, but the product of the halogenation does have two chiral centers. I would put one on a dash and one on a wedge to show the anti addition.
Awesome! Keep up your brilliant effort. It's very2 helpful!
Thank you! :)
I love your videos but I seem to need some background to understand this one because I could not be more lost. What is the prequel to this video? I was following the playlist/series..?
Think of this video as a short summary of all of the other alkene reactions presented in the series. As such, I would watch this video either first (as a preview of what’s to come) or watch it last (as a quick review of everything). For the entire series, in correct order, visit my website at leah4sci.com/alkene-reactions
Im not sure if you realized but you contradicted yourself for the halohydrin. you mentioned that the halogen goes to the less substituted (markovnikov because more H bonds) but then you said that this is a markovnikov reaction because the solvent without the H adds to the more substituted carbon which is the opposite of markovnikov.
Dejure Jones omg I’m so glad you saw that too!
Thanks for watching and for your comment! I do not believe I contradicted myself. Halohydrin formation is a Markovnikov reaction because the nucleophile (in this case, the polar protic solvent) adds to the more substituted carbon. It is the solvent, not the halogen, that adds last in the reaction mechanism. For the complete breakdown of the reaction mechanism, visit leah4sci.com/halohydrin-formation/
My textbook (Wade) says that Oxymercuration-Demurcation/Alko... has no stereochemistry, so there's no Anti/Syn
From a stereochemical perspective, oxymercuration is an anti addition. This has to do with the formation of the mercurinium ion as an intermediate. The nucleophile cannot attack from the same side as the mercury because of steric hindrance. If you’d like to further break down any statements from your textbook, I’d love to do so in my Organic Chemistry Study Hall. For more information, go to studyhall.leah4sci.com/join
thank you Leah!
-love from Seattle
You're welcome. :)
at 4:07 why does it look like both bromines are added to the same side? If the reaction is supposed to proceed with anti stereochemistry doesn't that mean both Br atoms come from opposite faces of the double bond? You only form the trans isomer right?
while you are absolutely correct this version of the product does not show stereochemistry as denoted by the lines rather than dashes and wedges. It does however state 'anti' to remind you that this is an anti addition
Your videos are just mind blowing and amazing.
Can you please make videos providing cheat sheets for chapters like carbonyl compound, carboxylic acids, phenols and ethers?
My goal is to eventually cover all organic chemistry reactions
thank youso much maam that helped me a lot to revise for my paper day after tomorrow tahnks a lot u almostsaved e wish me luck
Glad I could help!
Excellent ,awesome ,fantastic ,fabulous
Thanks so much!
4:46 ma'am could you kindly explain why the hydroxyl group didn't go to the more substituted tert carbon next door ?
To understand, we need to look more closely at the mechanism of the halohydrin formation. There is no carbocation intermediate formed, but rather a halonium ion which stabilizes the positive charge and prevents rearrangement. Check out more on this mechanism by visiting leah4sci.com/halohydrin-formation-alkene-reaction-mechanism/
thank you, your video are very helpful.
You're so very welcome, happy to help
Great video, really helped me realize and remember certain things about each reaction! Thanks!
That's great! You're welcome Sierra :)
I'm gonna fail my test :(
join the club. i have a borderline failing average and am the top quarter of my class or so.
What did you do?
Big mood
Me too T_T
heyy it’s been two years, did you pass?
Perfect video, thank you
You're welcome!
Hello leah can you check back the oxidative cleavage with hot KMnO4 in your cheat sheet..? the 2nd products in the cheat sheet gives formic acid (HCOOH) but in your video 11:57 it gives CO2
I'm guessing the CO2 as the 2nd product is correct. After cleavage the unsubstituted carbon should become CO2, monosubstituted become COOH and disubstituted become ketone
Yes, you are absolutely right! Thank you for pointing this out. The correct second product of the oxidative cleavage reaction with KMnO4 would be CO2. A terminal carbon on an alkene will be fully oxidized. Again, thank you! We will correct the alkenes cheat sheet on our site.
for the last reaction, cyclopropanation an alkene can be reacted with CH2N2/UV light for the same product?
Yes, those are also acceptable reagents for the cyclopropanation of an alkene.
hii, thanks for the video, it was really helpful. but im still a bit confused at the Halohydrin process, according to what u said it should be following mark's rules, but if thats the case, why does the H-shift from tert-C to sec-C doesnt happen to form tert-Carbionium ion, since it would be more stable, and the end product would then be 4bromo 2methyl 2ol butan ?
i am having my finals next week and now im going through all of your videos, they are really helpful, thank you so much
im currently thinking its because of the intermediate, where both C of the double form form a bond with Br, which gives them the positive partial charge, and the H-shift doesnt like the positive charge so much, but the OH- ion does, thats why the OH-Ion jump right into the sec-C, but wouldnt that make it an anti marks product?
The intermediate is the key here! Rather than having any sort of hydride shift, what we see in this mechanism is the formation of a halonium intermediate where the halogen (in this case, bromine) forms a bridged intermediate across the former pi bond. But even in this bridged intermediate, we see a preference for the partial positive charge to fall on the more substituted position. Therefore, the alcohol comes in and attaches to that more substituted carbocation (the Markovnikov position) in the second step.
For more on the mechanism of the halohydrin formation, make sure to see my video at Leah4sci.com/halohydrin
@@Leah4sci Thanks for the explaination x)
I had my orgo 1 final today and your videos really helped me a lot !
at 4:43 shouldn't the oh group attach to the tertiary carbon because of the stability of the 3° cabocation?
I was thinking the same thing. I expected a hydride shift
In this case there is no carbocation intermediate. The nucleophile (H2O) attacks the delta positive carbon on the bromonium. Because there's no true carbocation, no rearrangement
There's no 'free' carbocation in this reaction. Instead it's a partially positive carbon held in place by the bromonium. OH is attracted to the partially positive carbon and IN attacking, breaks the carbon-bromine bond. Without a free carbocation there is no shift
It really helpful ... thank you so mach ....
Glad it helped! You're welcome :)
quick question, so these are just different ways/methods in breaking an alkene? because if so, these different ways can also be used with organic synthesis reactions? btw, your videos have helped me so much! so thanks for posting these great videos :)
These are the different ways for reacting alkenes, yes