Chapter 20, Problem 67P

Interpretation Introduction

Interpretation:

The mechanism for the elimination step in the Wohl degradation is to be drawn.

Concept Introduction:

In Wohl degradation, the first step is aldose carbonyl group is converted to the oxime.  Then oxime is dehydrated by an acetic anhydride to give the nitrile (a cyanohydrin).  The formation of cyanohydrin is reversible in nature.  It undergoes a basic hydrolysis to give aldose with one less carbon with a loss of $\text{HCN}$ molecule.