Chapter 24, Problem 31P

Interpretation Introduction

Interpretation:

The possible number of ketopentoses is to be determined, and their Fischer projections are to be drawn.

Concept introduction:

A ketopentose is a carbohydrate with a five carbon chain and a ketone functional group at C2.

Fischer projection is used to represent the stereochemistry in chiral molecules, particularly carbohydrates.

Fischer projection of a carbohydrate is drawn with the carbon chain vertical, and the lowest numbered carbon at the top. In case of aldoses, this means the aldehyde group, at C1 is at the top. For ketoses, the keto group is at C2, with C1 at the top.

The non-terminal groups are shown on horizontal bonds.

The horizontal bonds in the projection are oriented toward the observer, and the vertical bonds oriented away from the observer.