Question

Question:Devise a synthesis of compound A from the given starting materials. You may use any other inorganic reagents or organic alcohols. A was used to prepare aliskiren, a drug used to treat hypertension (see also Problem 5.7).

Short answer

Answer

Step-by-step solution

Formation of 3-(3-bromopropoxy)-4-methoxybenzaldehyde

The phenolic -OH group of the compound can be converted to a phenoxide ion upon treatment with a strong base. The phenoxide ion hence formed can react with 1,3-dibromopropane.The reaction is given below:

Formation of3-(3-bromopropoxy)-4-methoxybenzaldehyde

It is further treated with sodium methoxide as shown below:

Formation of 3-(3methoxypropoxy)-4-methoxybenzaldehyde

Conversion of aldehyde to alkyl bromide

The aldehyde group can be reduced via a Clemmenson reduction. The methyl group can be converted to alkyl bromide by treating it with bromine in the presence of light.

The reaction is given below:

Clemmenson reduction and bromination