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Need hekp with e/z isomerism

IMAG0111.jpg can anyone help me stub 5dii) this is the answer
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one of the answer is that one of the carbon is attached to two different group but H is not one of them. How can this work though because the question under it says you need to have a H attached to the c in order to form e/z isomerism. '(In order to have cis or trans isomers) each C atom of the CC double bond must have two different substituent groups and one of those groups must be hydrogen.' Can anyone explain this? Thanks.
(edited 7 years ago)
It's asking you to draw the structural formula of hex-2-ene.
Since isomers have the same molecular formula but different structural formula, it's asking you to draw the possible isomers of hex-2-ene. Hope that helps
Reply 2
E-Z requires each carbon with the double bond must be attached to two different things.

W.........X
...\......./
...C=C
.../.......\
Y.........Z

W is not the same a Y and X is not the same as Z

For cis-trans, W = X or Z OR Y = X or Z.
Reply 3
Original post by Pigster
E-Z requires each carbon with the double bond must be attached to two different things.

W.........X
...\......./
...C=C
.../.......\
Y.........Z

W is not the same a Y and X is not the same as Z

For cis-trans, W = X or Z OR Y = X or Z.


Hi, thanks for helping I am not just not sure whether one of the two different groups has to be hydrogen as that's what is needed for cis-trans isomerism. So if I have CH3 and CH2 one one side, this wouldn't count as e/z isomerism because one of them has to be hydrogen right?
Reply 4
Original post by coconut64
Hi, thanks for helping I am not just not sure whether one of the two different groups has to be hydrogen as that's what is needed for cis-trans isomerism. So if I have CH3 and CH2 one one side, this wouldn't count as e/z isomerism because one of them has to be hydrogen right?


That looks like the old (F322) OCR A cis-trans definition, which seemed to imply that there had to be a H at both ends of the double bond.

Rest assured, there just has to be a group the same at both ends. If that group happens to be a H, then so be it.

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