Compound A is an optically active alcohol. Treatment with chromic acid converts A into a ketone, B. In a separate reaction, A is treated with PBr3, converting A into compound C. Compound C is purified, and then it is allowed to react with magnesium in ether to give a Grignard reagent, D. Compound B is added to the resulting solution of the Grignard reagent. After hydrolysis of the initial product (E), this solution is found to contain 3,4 dimethylhexan-3-ol. Propose structures for compounds A, B, C, D, and E.

The compound that bears one or more hydroxide groups (OH) is called alcohol. The alcohols have very large applications in organic synthesis. It has wide applications in perfume and cleaning agents.

Compound A is butan-2-ol. When it is treated with PB₃, it forms 2-bromobutane. So the compound C is 2-bromobutane. When it is treated with magnesium metal in the ether it forms sec-butylmagnesium bromide. So, compound D is sec-butylmagnesium bromide.

When butan-2-ol is treated with NaOCl/HOAc it gives butan-2-one. So, compound B is butan-2-one. When sec-butylmagnesium and butan-2-one react together, there will be the formation of magnesium 3,4-dimethylhexan-3-olate bromide. So, compound E is magnesium 3,4-dimethylhexan-3-olate bromide. When it is acidified, 3,4-dimethylhexan-3-ol is formed. So, the final compound is 3,4-dimethylhexan-3-ol. The reaction is shown below.