if only u would know how many videos i watched to understand this yet this is the only video that helped me !!! Thank you so muchh God bless your soul wonderful personnn!!!
Nice video. Good review for finals. However, one of the cyclohexane as you have as an example, having chlorine and a methyl group attached to it, do not have chiral centers but are diasteriomers. When comparing two molecules, they do not need chiral centers to be diasteriomers.
I'm crying, I couldn't pass our chemistry quiz and I am struggling differentiating these compounds. I am left behind because I still have a lot of chores in our house and I couldn't manage my time well. I might fail this semester, scared and pressured.
Sir, at 3:30 1-Chloro-4-methylcyclohexane. Does it have any chiral centers? If it does not, how can we give it R S configuration? and how can we know it has stereoisomers without R S configuration?
Great and informational video. Keep in mind that your fourth example included a molecule with no stereo centers because the right and left sides were the exact same. Therefore, it would be Achiral molecules.
i really dont see how carbon 5 is the same carbon five as the other molecule when the second chair has cl and br separated by much less carbons than the first chair
If I’m understanding what you’re saying, I was taught when drawing chair confirmation it doesn’t matter in what way we count the substantiates. (Clockwise or counter clockwise) you will still get the same answer
In my exam, they showed a line-structure and a newman structure. It threw me off, I can only distinguish them when I build an actual model using the modeling kit. But this help also, thank you.
Can you explain how you got identical for the first two chair conformations? They appear to be the same, but the chlorine is attached to the different carbons(the left one on 3, and the right one at 5) when counting in the clockwise direction. When using the R/S configuration system, I got (R,R) for the compound on the left and (S,S) for the right which means they are enantiomers... Am I doing something wrong?
Hey mark, you are doing something wrong. Starting with the molecule on the left, counting in a clock wise fashion, on carbon 1, the chlorine is going down, on carbon 5 the bromine is going up. Switch to the molecule on the right, REMEMBER when you do the flip, the carbon with the chlorine is now your carbon 1. So on carbon I see the chlorine going down. counting ANTI-CLOCKWISE this time since its a flip, the bromine on carbon five is going up. draw the cyclic structures for both and they are the same.
If you build the molecules for the first two, you will see that there is no way possible for those to be identical, unless you perform surgery on the molecule and move the atoms to inverted positions, which makes it a constitutional isomer, not identical. The only way to make those identical is to switch positions
The way you have numbered the first two conformations is incorrect. It has to be the lowest number. For instance, you've counted 1-3 instead of 1-5. That's why people were confused. Thanks for the vid though.
@@KevanScience do you think you could do an example video on a big chiral compound like estrogen for identifying R/S? I had a quiz on one and it took me too long to work it out and I want to learn shortcuts to be more efficient identifying stereo centers and assigning R and S to each center.
In your third illustration, 1-chloro-3-methylcyclopentane, how does it have 2 chiral centres? Ain't both sides of carbon joined with methyl and chlorine contain same group, (-CH2-) ? Please clarify, this has constantly been my confusion since very long time...
Hey Mohit, that's a great question. Lets take a look at the one on the left first. Looking at the chiral carbon with the -CH3 having a wedge. The carbon has a (CH3), a Hydrogen. Now look, if I step 1 carbon away from each sides, I hit a CH2 which we cannot make any conclusion that they are different THINGS since they are both CH2'S. With that being said, we have to go another carbon out on both sides. When this happens, a CHLORINE atom is clearly present on one side, while i still have another CH2 on the other side. This is why the carbon is chiral because it has 4 DIFFERENT SUBSTIUENTS BONDED to it. It has a Hydrogen, A Ch3, a CH2CHCL, and a CH2CH2. This is also true for the other chiral center. Hope this clarifies everything.
Okay, that makes sense, now, suppose if we have para- Xylene (1,4-dimethylbenzene), then, by this rule this compound must not have any chiral centre, while if it were meta xylene it must have 2 chiral centres, right?
No, that is incorrect. Again, when we talk about chirality and an atom being chiral, 4 DIFFERENT THINGS has to be bonded to the atom itself. In the benzene ring, it is conjugated, meaning, we have double bonds. This means at any given time, I can only have three different things bonded to one of those carbons. In this case, none of them would have chiral centers. Always remember, 4 DIFFERENT THINGS MUST BE BONDED, NOT 3 like in this case or two or one. It must be FOUR. Good question again.
Oh sorry, i forgot that those carbon in ring are sp2 hybrid, so, the same question now turns to 1,4-dimethylcyclohexane must not have chiral carbons, whereas 1,3-dimethylcyclohexane must possess 2 chiral carbons. Is this true? Or am I again missing out on something?
Should I assume for the last examples H is always a neutral line? If I give it its respective wedge/dash and flip it your rules for identical molecules don’t work. You get a S,S in the original one and S,S for mirrored and dashes/wedges alternating. Should it not be R,R? To confirm identical
Can someone please answer this, Diastereoisomers mean at least 2 Shift to make a stereoisomer. So why here we are saying if 2 kept same and 1 changed it’s a Diastereoisomer? Or am I confusing them with mirror image?? Can someone please explain! 😅
Wait I think I got it now but please if my explanation is wrong please feel free to correct me. I think we said 1 kept same 1 changes, when “flipping” “inverting” it creates a stereoisomer because in such case there will always be a different 3D arrangement. Since (1 kept same 1 changes). So that’s what makes it a steroisomer Or i think I am confusing what a stereoisomer is with a diastereoisomer. Please help I think I am just digging a rabbit hole 😶
This video is so confusing and misleading. Doesn’t every chiral center change in the first one? He’s randomly using different methods without anything systematic, plus the first one is wrong....
I have been struggling with differentiating between these three for SOOO many days, Finally, you explained it clearly. Thank you VERY MUCH sir
i watched literally 6 different videos on this and yours is the only one that helped. thank you king
I am gonna cry ... FINALLY i found someone who differentiates properly between them ! Thanks for saving me before exam .. wish i had you as my Dr.
if only u would know how many videos i watched to understand this yet this is the only video that helped me !!! Thank you so muchh God bless your soul wonderful personnn!!!
Same , the last part is so lit!
This is the best video on steorochemistry. Better than Khan Academy.
Thanks a lot the difference between identical and enantiomers can be confusing but you did an excellent job breaking it down.
This was very helpful! I really appreciated the way you explained this concept as I wasn’t able to get it beforr
wow kevan u really made it easy ..thank u so much..it'll help me a lot during my upcoming exams..
thank you for this video!!! that last part helped clarify a detail that's been tripping me up for days
i love u u saved my organic chem with this video
Watching this one hour before my exam i almost cried that im finally able to understand this
This was sooooooo helpful, please make more like this!
I cannot express how much this helped
this was INCREDIBLY helpful, thank you so much!!
Nice video. Good review for finals. However, one of the cyclohexane as you have as an example, having chlorine and a methyl group attached to it, do not have chiral centers but are diasteriomers. When comparing two molecules, they do not need chiral centers to be diasteriomers.
I saw that too
the only video that actualy helped me tysm king
I'm crying, I couldn't pass our chemistry quiz and I am struggling differentiating these compounds. I am left behind because I still have a lot of chores in our house and I couldn't manage my time well. I might fail this semester, scared and pressured.
how did you do?
Extremely clear and helpful, thanks a ton!
This was sooo helpful omg thank you, greeting from Switzerland!!
You're so welcome!
Sir, at 3:30 1-Chloro-4-methylcyclohexane. Does it have any chiral centers? If it does not, how can we give it R S configuration? and how can we know it has stereoisomers without R S configuration?
Amazing video Kevan. Extremely helpful!!!
Great and informational video. Keep in mind that your fourth example included a molecule with no stereo centers because the right and left sides were the exact same. Therefore, it would be Achiral molecules.
i really dont see how carbon 5 is the same carbon five as the other molecule when the second chair has cl and br separated by much less carbons than the first chair
If I’m understanding what you’re saying, I was taught when drawing chair confirmation it doesn’t matter in what way we count the substantiates. (Clockwise or counter clockwise) you will still get the same answer
this helped IMMENSELY. merci beaucoup!!
Enantiomer = all chiral centers are changing, diasterometers = one of the chiral centers is same (ie: if one was up/out, it is still up/out)
How in the world are some of these CLEARLY not mirror images, yet are enantiomers?
finally i understand the difference between identical and enantiomers
THIS IS SO HELPFUL THANK YOU SO MUCH SIR!!!
In my exam, they showed a line-structure and a newman structure. It threw me off, I can only distinguish them when I build an actual model using the modeling kit. But this help also, thank you.
Can you explain how you got identical for the first two chair conformations? They appear to be the same, but the chlorine is attached to the different carbons(the left one on 3, and the right one at 5) when counting in the clockwise direction. When using the R/S configuration system, I got (R,R) for the compound on the left and (S,S) for the right which means they are enantiomers... Am I doing something wrong?
Hey mark, you are doing something wrong. Starting with the molecule on the left, counting in a clock wise fashion, on carbon 1, the chlorine is going down, on carbon 5 the bromine is going up. Switch to the molecule on the right, REMEMBER when you do the flip, the carbon with the chlorine is now your carbon 1. So on carbon I see the chlorine going down. counting ANTI-CLOCKWISE this time since its a flip, the bromine on carbon five is going up. draw the cyclic structures for both and they are the same.
If you build the molecules for the first two, you will see that there is no way possible for those to be identical, unless you perform surgery on the molecule and move the atoms to inverted positions, which makes it a constitutional isomer, not identical. The only way to make those identical is to switch positions
I also am confused. I worked it out and got enantiomers
no as i thing, you are to be right because, you have an effort for reach your goal.
The way you have numbered the first two conformations is incorrect. It has to be the lowest number. For instance, you've counted 1-3 instead of 1-5. That's why people were confused. Thanks for the vid though.
Thank you so much, great video! You are gifted. God bless you!!!!
It was actually perfect , thank you 💜
Thanks ! From France
Thank you so much for simplify this
Very good examples, thank you!
I gotchu 😉
@@KevanScience do you think you could do an example video on a big chiral compound like estrogen for identifying R/S? I had a quiz on one and it took me too long to work it out and I want to learn shortcuts to be more efficient identifying stereo centers and assigning R and S to each center.
@@daniellai7601 sure, look for that video in about 5 hours later tonight
@@KevanScience you’re the absolute best thank you! I’ll put my notifications on for your channel
Just loved your explanation ....Thanks a ton sir😊✨
THANK YOU SO MUCH KING! 🐐
super simple explanation AMAZING
Duuude thank you for this
gotcha!
This was great practice :) thank you good sir
My profesor has us identify the first problem as Conformational isomers (Conformational enantiomers or conformational diastereomers) any idea why?
Thank you! Awesome video!
I enjoyed your explanation
This is really helpful, thank you so much!
Thankyou! Love your content. Clear and concise!
Gotchu Ruohan!
I WISHED I SAW THIS BEFORE MY EXAM ENDED
very well explained. Thank you!
Thank you so much, this was so helpful.
Thank you!!! Helped a lot!!
bro made my 2 hour lecture make more sense in 7 minutes
Thanks for the help Kevan!
WOOOOOOOOOW! LOVE THE TRICK!
Best explanation ever
whats a chiral center that you said were the same and were changing at the end?
Thank you for helping me understand this
WoW that was very clear
Excellent brother !
Thank you very much for making this video!!!!!!!
In your third illustration, 1-chloro-3-methylcyclopentane, how does it have 2 chiral centres? Ain't both sides of carbon joined with methyl and chlorine contain same group, (-CH2-) ?
Please clarify, this has constantly been my confusion since very long time...
Hey Mohit, that's a great question. Lets take a look at the one on the left first. Looking at the chiral carbon with the -CH3 having a wedge. The carbon has a (CH3), a Hydrogen. Now look, if I step 1 carbon away from each sides, I hit a CH2 which we cannot make any conclusion that they are different THINGS since they are both CH2'S. With that being said, we have to go another carbon out on both sides. When this happens, a CHLORINE atom is clearly present on one side, while i still have another CH2 on the other side. This is why the carbon is chiral because it has 4 DIFFERENT SUBSTIUENTS BONDED to it. It has a Hydrogen, A Ch3, a CH2CHCL, and a CH2CH2. This is also true for the other chiral center. Hope this clarifies everything.
Okay, that makes sense, now, suppose if we have para- Xylene (1,4-dimethylbenzene), then, by this rule this compound must not have any chiral centre, while if it were meta xylene it must have 2 chiral centres, right?
No, that is incorrect. Again, when we talk about chirality and an atom being chiral, 4 DIFFERENT THINGS has to be bonded to the atom itself. In the benzene ring, it is conjugated, meaning, we have double bonds. This means at any given time, I can only have three different things bonded to one of those carbons. In this case, none of them would have chiral centers. Always remember, 4 DIFFERENT THINGS MUST BE BONDED, NOT 3 like in this case or two or one. It must be FOUR. Good question again.
Oh sorry, i forgot that those carbon in ring are sp2 hybrid, so, the same question now turns to 1,4-dimethylcyclohexane must not have chiral carbons, whereas 1,3-dimethylcyclohexane must possess 2 chiral carbons. Is this true? Or am I again missing out on something?
Yes, this assumption is true.
Loved the video, it helped very much. thank you.
Very helpful, thank you 🙏🏻
Can you tell me the ingredients and how to mix crystal meth and MDMA, please?
Very helpful one.Thank you very much
Outstanding!! Very helpful
I understand now! Thank you so much!
No problem.
Perfect. Thank you very much! Greetings from Germany. 👍👍👍👍💥
Should I assume for the last examples H is always a neutral line? If I give it its respective wedge/dash and flip it your rules for identical molecules don’t work.
You get a S,S in the original one and S,S for mirrored and dashes/wedges alternating. Should it not be R,R? To confirm identical
Very helpful thanks
SO USEFUL OMG
This is such a great video, thank you so much!!!
You are amazing!!!❤❤❤❤
Thankyou this helped a lot
big thank you sir!
thaaaaaaaaankssssss you saved my life :)))))
This gets so confusing in books thanks greetings from india❤️❤️
Thank u you help me a lot
I gotchu ❤️
Can someone please answer this,
Diastereoisomers mean at least 2 Shift to make a stereoisomer.
So why here we are saying if 2 kept same and 1 changed it’s a Diastereoisomer?
Or am I confusing them with mirror image?? Can someone please explain!
😅
Wait I think I got it now but please if my explanation is wrong please feel free to correct me.
I think we said 1 kept same 1 changes, when “flipping” “inverting” it creates a stereoisomer because in such case there will always be a different 3D arrangement. Since (1 kept same 1 changes).
So that’s what makes it a steroisomer
Or i think I am confusing what a stereoisomer is with a diastereoisomer.
Please help I think I am just digging a rabbit hole 😶
thank you, helped a lot
Thank you so soooooooooooooooooooo much
gotcha!
Ur a legend ❤
great video
so helpful thankyou
This video is so confusing and misleading. Doesn’t every chiral center change in the first one? He’s randomly using different methods without anything systematic, plus the first one is wrong....
Perfect video.. Thank man
Fantastic
Thank you!!!
Thank you sir!
Thx!💜
Thank you
Sir can you tell me that is gas molecules are identical?? According to modern research??
I'm sorry I don't understand what you are asking. Ask one more time.
If I'm not mistaken, are you asking if ideal gas molecules are identical ?
Yes
With R and S can't it be simple?
Thanks soooooo much Kevan!!!!!!!!!!!!!!!!!!!!!! I appreciate you so much
No problem.
thank you!
Thank you sir
1.20. I guess numbering the carbon is not correct.. plz clarify it... its video is really helpful in stereo chem.
though the numbering is wrong, it doesn't create a change!
ty!!
I cant understand
Nice video sir .. thanks
You rock! Thank-you!
No problem Chezna.
Thanks so much man