Question

Which of the following reaction do not present in the major product of the given Birch reductions

• A. (i), (iii), (vi)
• B. (iv), (vi), (vii)
• C. (iv), (v), (vi)
• D. (i), (ii), (v), (vii)

Answer 1

Answer: (B)

(iv), (vi), (vii)

As refer to the IMAGE $01$, in Brich reduction, the benzene is converted to a diene and occurs through carbanion and free radical mechanism.

Since, it is an electron withdrawing group. Double bond is not attached with the group. $Na$ in liquid $N{H}_3$ is a reducing agent which converts triple bond into trans double bonds.

As refer to the IMAGE $02$ due to the conjugation, only one double bond is lost.