Question

Question: Which of the following alcohols could notbe made selectively by hydroboration–oxidation of an alkene? Explain.

Short answer

Answer

Possible

Step-by-step solution

Step 1: Anti-markovnikov’s rule

In hydroboration-oxidation reaction two steps occur:

• Hydroboration- It occurs in an anti-Markovnikov manner, where hydrogen (from BH₃) attaches to the more substituted carbon and BH₂to less substituted carbon in double-bonded carbon. It is syn addition which means that the hydroboration takes place on the same face of the double bond.
• Oxidation step involves the replacement of BH₂ with hydroxyl group.

 Step 2: Alcohol possible or not:

Given alcohol is possible when a double bond is between C₂and C₃ as both are equally substituted so can attach to any side. Other alcohol possible is the same as given. Thus, this alcohol is made selectively.