Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Draw and label the E and Z isomers of each of the following :
1. CH₃CH₂CH=CHCH₃ 2. CH₃CH₂C(Cl)=CHCH₂CH₃
3. (n-Bu)(Et)C=C(CH₂Cl)(i-Pr) 4. HOCH₂CH₂C(CHO)=C(C≡CH)(C(CH₃)₃)
Options:
Answer:
Solution:
1. Pent-2-ene. Z-isomer (the two chain carbons on the same side) :
E-isomer :
2. CIP priorities : at C-2, Cl C₂H₅; at C-3, C₂H₅ H. Z-isomer (Cl and C₂H₅ on the same side) :
E-isomer :
3. CIP priorities : at the left carbon n-Bu Et (at the second atom (C, H, H) beats (H, H, H)); at the right carbon CH₂Cl i-Pr (Cl C). Z-isomer :
E-isomer :
4. CIP priorities : at the left carbon CHO CH₂CH₂OH (O, O, H beats C, H, H); at the right carbon C≡CH C(CH₃)₃ (the triply bonded carbon is treated as bonded to (C, C, C), and at the next point of difference (C, C, H) beats (H, H, H)). Z-isomer :
E-isomer :
