Q104 · CSIR-NET Chemistry, December 2019
Paper: CSIR-NET December 2019 · Subject: Organic Chemistry · Chapter: Pericyclic Reactions · Topic: Pericyclic Reactions – General · Marks: 2 · Difficulty: Medium
The intermediate A and the major product B, formed in the following reaction are 
[A] $\xrightarrow{\Delta}$ [B]
[A] $\xrightarrow{\Delta}$ [B](a)[A] = 
[B]= 
[B]= (b)[A] = 
[B]= 
[B]= (c)[A] = 
[B]= 
[B]= (d)[A] = 
[B]= 
[B]= Answer
Answer: B ✓ checked by 4AB · confidence medium
The source book printed A; on checking, B is correct — see the explanation.
Explanation
Lindlar reduction gives the all-Z central tetraene A. Heating drives an 8π conrotatory then a 6π disrotatory closure. The product is the bicyclo[4.2.0]octadiene with trans CH₂OH-bearing groups (b).
Study loop for Pericyclic Reactions