Question

Starting with benzene and any other reagents you need, show how you would synthesize the compound shown here. (Hint: Consider a Pd-catalyzed coupling for the final step).

Short answer

In the presence of aluminum chloride, an acyl chloride reacts with benzene to give acetophenone. This reaction is known as Friedel crafts acylation reaction. Keto group is meta director so incoming electrophile attacks meta to keto group. The formed acetophenone undergoes chlorination (electrophilic substitution reaction) to give 3-chloroacetophenone.

Step-by-step solution

Formation of 3-chloro acetophenone

In the presence of aluminum chloride, an acyl chloride reacts with benzene to give acetophenone. This reaction is known as Friedel crafts acylation reaction. Keto group is meta director so incoming electrophile attacks meta to keto group. The formed acetophenone undergoes chlorination (electrophilic substitution reaction) to give 3-chloroacetophenone.

Formation of the desired product

The heck coupling reaction is a palladium-catalyzed cross-coupling reaction in which alkyl halide reacts with an alkene to give the substituted product in a basic medium. The compound,3-chloroacetophenone undergoes a heck coupling reaction with but-1-ene to give the desired product.