Question

Major products A and B formed in the following reaction sequence , are

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Answer 2

1. In the first step , $PBr_3$ replaces $-OH$ with $-Br$: $CH_3C(OH)CH_2CH_3 \rightarrow CH_3CH(Br)CH_2CH_3$ (A).

2. In the second step , alcoholic $KOH$ causes elimination of $HBr$: $CH_3CH(Br)CH_2CH_3 \rightarrow CH_3CH=CH_2$ (B).