Question

Question: Devise a synthesis of each compound from the indicated starting material.

Short answer

Answer

Step-by-step solution

Step 1:Hydroboration-oxidation reaction

It involves the syn addition of $\mathit{H}\mathbf{-}\mathit{B}{\mathit{H}}_{\mathbf{2}}$ to the double bond, and it occurs only in one step. There is no rearrangement in this reaction.

Formation of products for a and b

a.

The reaction of 1-bromobutane with potassium 2-methylpropan-2-olate gives but-1-ene. This is followed by chlorination in the presence of alcohol to form the desired product.

The reaction is shown below:

Product formation in a

b.

The reaction of 1-methylcyclohexanol with sulfuric acid gives 1-methylcyclohex-1-ene.

This is followed by hydroboration-oxidation to form the desired product. The reaction is shown below:

Products formation in b