Chapter 20.5, Problem 11P

Interpretation Introduction

Interpretation:

The aldohexoses and ketohexoses that are formed when D-tagatose is added to a basic aqueous solution are to be identified.

Concept Introduction:

In the enediol rearrangement of a monosaccharide, the base removes the proton from the $\alpha$-carbon resulting in the formation of enolate ion.  After the deprotonation, enediol is formed resulting in the formation of aldohexose and ketohexose by the base-catalyzed conversion.