Chapter 8, Problem 41P

Interpretation Introduction

Interpretation:Compound that is intended for synthesis by student after aqueous workup should be given and the reason behind the unexpected formation of tertiary alcohol and the manner it is formed should be given.

Concept introduction:Grignard reagents are alkyl magnesium halides obtained from the treatment of haloalkane with magnesium in the presence of dried ether conditions. These reagents are useful precursors for the quick synthesis of a variety of organic compounds For example, the reaction of the Grignard reagent with aldehyde or ketone generates alcohol as illustrated below.

  

Methyl bromide reacts with magnesium ether to give Grignard reagent. This Grignard methylmagnsium bromide on treatment with formaldehyde gives corresponding alcohol. The mechanistic pathway for the latter reaction is as follows:

  

The polar carbonyl bond breaks and the polar Grignard reagent attack at electron-deficient carbon. Finally with the hydrolysis and work up the alcohol is formed.