Question

which is the best method for the following transformation? a. 1. bh₃, thf 2. h₂o₂, oh⁻ b. h⁺, h₂o c. concentrated h₂so₄ d. 1. hg(oac)₂, h₂o 2. nabh₄

Explanation:

Step1: Analyze each option

• Option A: Hydroboration - oxidation reaction. In this reaction, \(BH_3\) adds to the double - bond in an anti - Markovnikov manner (the boron attaches to the less - substituted carbon of the double - bond). Then, oxidation with \(H_2O_2/OH^-\) converts the \(C - B\) bond to a \(C - OH\) bond, resulting in an alcohol with anti - Markovnikov orientation.
• Option B: Acid - catalyzed hydration (\(H^+/H_2O\)) follows Markovnikov's rule (the \(OH\) group adds to the more - substituted carbon of the double - bond).
• Option C: Concentrated \(H_2SO_4\) is not a reagent for direct conversion of an alkene to an alcohol. It can be used in the formation of alkyl hydrogen sulfates (in the first step of some hydration reactions, but not the final product as an alcohol without further hydrolysis).
• Option D: Oxymercuration - demercuration (\(Hg(OAc)_2/H_2O\) followed by \(NaBH_4\)) follows Markovnikov's rule (the \(OH\) group adds to the more - substituted carbon of the double - bond).

Step2: Compare with the required transformation

The given transformation is the conversion of an alkene to an alcohol with anti - Markovnikov orientation. Hydroboration - oxidation (Option A) is the reaction that gives an alcohol with anti - Markovnikov orientation.

Answer:

A. 1. \(BH_3\), THF 2. \(H_2O_2\), \(OH^-\)