Chapter 21, Problem 42P

Interpretation Introduction

Interpretation:

The hexose obtained after three successive Killiani-Fisher synthesis of (+)-glyceraldehyde is to be predicted on the basis of given information.

Concept Introduction:

In Killiani-Fisher synthesis, hydrogen cyanide attacks the carbonyl group.  The carbonyl carbon is converted to an asymmetric center.  The $\text{C}\equiv \text{N}$ bond is reduced to an imine which is partially deactivated by palladium catalyst to prevent the reduction of imine to an amine.  The two imines are hydrolyzed to two aldoses.