Chapter 17, Problem 17.75P

Interpretation Introduction

Interpretation:

Structures of compounds $\text{K-V}$ in the given reaction sequence are to be determined.

Concept introduction:

Imine is formed as a product when nitrile reacts with Grignard reagent.

Lithium aluminum hydride $\left({\text{LiAlH}}_{\text{4}}\right)$ is a source of hydride ${\text{(H}}^{\text{-}})$ and acts as nucleophile. The strong base sodium hydroxide $\text{(NaOH)}$ abstracts a proton formed nucleophile.

Phosphorous tribromide ${\text{(PBr}}_{\text{3}}\text{)}$ can convert primary and secondary alcohol to alkyl halide via back-to-back ${\text{S}}_{\text{N}}\text{2}$ reactions.

The Hofmann elimination reaction leads to an anti-Zaitsev elimination product or Hofmann product. An amine with a poor leaving group is converted to a tetraalkyl ammonium ion, which has a moderately good leaving group, using excess of an alkyl halide like ${\text{CH}}_{\text{3}}\text{I}$. Subsequent treatment followed by heat induces elimination.

Sodium hydride (NaH) is an ionic hydride, and thus a strong base, but it is not nucleophilic.