Chapter 16, Problem 16.22P

Interpretation Introduction

Interpretation:

With respect to the given condition, the structure of the major product formed by the reaction of methylmagnesium bromide with 4-tert-butylcyclohexanone has to be predicted.

Concept introduction:

Alkyl or aryl magnesium halides (RMgX) are known as Grignard reagent. The Grignard reaction is an organometallic chemical reaction in which the Grignard reagent act as nucleophile and attack electrophilic carbon atom that are present within polar bonds to yield a carbon-carbon bond.

Synthesis of Grignard reagent is shown below,

$\underset{Alkyl/arylhalide}{R-X}+Mg\stackrel{Ether}{\to }\underset{Grignardreagent}{RMgX}$

The alkyl halide can be prepared from alcohol through different methods, preparing alkyl halide using thionyl chloride ($SOC{l}_2$) is one of the important method and it is shown below,

$R-OH\stackrel{SOC{l}_2}{\to }R-Cl+S{O}_2+HCl$

Addition of a Grignard reagent to an aldehyde/ketone followed by protonation will produce an alcohol.

Thus,

Reaction of Grignard reagent with formaldehyde yields primary alcohol. Secondary and tertiary alcohol can be prepared by the reaction of Grignard reagent with any aldehyde (except formaldehyde) and ketone respectively.