Q27 · CSIR NET Chemistry, December 2013
Paper: CSIR NET December 2013 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Marks: 2 · Difficulty: Medium
The major product formed in the following reaction sequence is: 
1. $\mathrm{BH_3}$, THF; $\mathrm{H_2O_2}$/NaOH 2. $\mathrm{Ph_3P}$, DEAD, 4-nitrobenzoic acid 3. $\mathrm{K_2CO_3}$, MeOH
1. $\mathrm{BH_3}$, THF; $\mathrm{H_2O_2}$/NaOH 2. $\mathrm{Ph_3P}$, DEAD, 4-nitrobenzoic acid 3. $\mathrm{K_2CO_3}$, MeOH(a)
(b)
(c)
(d)
Answer
Answer: A ✓ checked by 4AB · confidence medium
Explanation
Hydroboration of α-pinene from the face opposite the gem-dimethyl bridge gives isopinocampheol (OH trans to the C-2 methyl); Mitsunobu with p-nitrobenzoic acid inverts C-3 and K₂CO₃/MeOH cleaves the ester, giving neoisopinocampheol with OH cis to the methyl (a).
Study loop for Reagents, Reaction Mechanisms & Named Reactions