Chapter 20, Problem 81IP

Interpretation Introduction

Interpretation:

The three steps and the products formed in each steps involved for the conversion of compound-1 to compound-2 (metathesis substrate) should be drawn.

Concept introduction:

• NaH is a strong base which deprotonates an alcohol.
• $S_{N}2$Reaction: The $S_{N}2$ reaction is single step process, leaving group leaves the molecule and nucleophiles attack the molecule is single step process which is simultaneous process. Inversion of molecule will take place.
• DIBAH (Diisobutylaluminium hydride) reduces ester group to aldehyde group.
• Wittig reaction: This process allows the preparation of an alkene by the reaction of an aldehyde ( $\text{-CHO}$) or ketone ( $\text{-C=O}$) with ylides generated from a phosphonium salt. The geometry of the resulting cis, trans alkene depends on the reactivity of the ylide.

To identify: The product formed when given compound is treated with NaH followed by chiral 2-bromo ethyl ester.