Q44E - Organic Chemistry (Mcmurry)

Question

Identify the reagents a–c in the following scheme:

Step-by-Step Solution

Answer

a is $\mathrm{H}{}_2\mathrm{O}/{\mathrm{H}}^{+}$

b is HBr

c is ${\left({\mathrm{CH}}_3\right)}_2\mathrm{CuLi}$

Step 1: Alkene to alcohol conversion

Markovnikov's rule: Alkenes react with water in the presence of acid as a catalyst to form alcohols. In the case of unsymmetrical alkenes, OH is added to the carbon, having fewer hydrogen atoms.

Step 2: Alcohol to alkyl halide conversion

Alcohol, when reacting with HX where X is a halide, it results in the formation of alkyl halides.

Step 3: Alkyl halide to methyl alkyl conversion

Corey-House synthesis is a reaction that involves the reaction of a lithium divinylcuprate with an alkyl halide to form a new alkane.

Step 4: Reagents used

• Step1: As alkene to alcohol conversion is occurring $\mathrm{H}{}_2\mathrm{O}/{\mathrm{H}}^{+}$ is used here.
• Step 2: As alcohol to alkyl bromide conversion occurs, HBr is used as a reagent.
• Step 3: As alkyl halide to methyl, alkyl conversion is used as a reagent for methyl addition.