Question

Synthesize each compound from cyclohexanol using any other organic or inorganic compounds.

Short answer

a. The reaction involves halogenation of cyclohexane followed by the Grignard reaction with formaldehyde to form cyclohexylmethanol.

b. The first step is dehydration followed by epoxidation. The epoxide thus formed undergoes the Grignard reaction followed by oxidation to form 2-phenyl cyclohexanone.

c. Cyclohexanol is oxidized to cyclohexanone in the first step, followed by the Grignard reaction. The product is dehydrated, followed by hydrogenation to form propylcyclohexanol.

d. First step is the conversion of cyclohexanol to cyclohexyl methanol. The product is oxidized, and a Grignard reaction is carried out. The product is then oxidized to form benzophenone.

Step-by-step solution

Organic synthesis

A sequence of reactions that converts an organic starting material to the desired product is called organic synthesis.

Each reaction step in organic synthesis is called a synthetic step.

Organic synthesis generally involvesthe formation or breaking of carbon-carbon bonds, oxidation, or reduction reactions.

Grignard reaction in organic synthesis

One of the most crucial steps in organic synthesis is the formation of C-C single bonds.

The use of a Grignard reagent can effectively form carbon-carbon single bonds.

The carbon-magnesium bond in a Grignard reagent is polarized and can form an alkyl carbanion. This is added to electrophilic carbon in a polar bond to form C-C bonds.

Synthesis of given compounds from cyclohexanol

a. Cyclohexanol is first halogenated to form bromocyclohexane. The Grignard reagent formed from bromocyclohexane is reacted with formaldehyde to form the desired product.

Conversion of cyclohexanol to cyclohexylmethanol

b. Cyclohexanol is dehydrated to cyclohexene which is followed by epoxidation using m-CPBA. The epoxide undergoes a Grignard reaction with phenyl magnesium bromide followed by oxidation to form the desired product.

Conversion of cyclohexanol to 2-phenyl cyclohexanone

c. Cyclohexanol is oxidized to cyclohexanone.

Oxidation of cyclohexanol

This undergoes a Grignard reaction with propyl magnesium bromide to form a cyclohexanol derivative. Dehydrogenation of this product produces two possible products, both of which hydrogenates to form the desired product.

Conversion of cyclohexanone to propyl cyclohexane

d. Cyclohexanol is converted to cyclohexylmethanol by halogenation followed by a Grignard reaction with formaldehyde.

Conversion of cyclohexanol to cyclohexylmethanol

The cyclohexylmethanol is oxidized to formylcyclohexane.It reacts with cyclohexyl magnesium bromide, which is synthesized from bromocyclohexane. This is followed by oxidation to formthe desired product.

Conversion of cyclohexylmethanol to benzophenone