Chapter 19.13, Problem 20P

Interpretation Introduction

Interpretation:

The stereochemistry of the two chirality centres in isocitrate is to be assigned. Further whether the OH and H add to the Si face or Re face of the double bond is also to be stated.

Concept introduction:

When an achiral molecule such as an alkene, with a sp² hybridized carbon, is converted into a chiral molecule, which enantiomer will result depends on the face of the planar carbons in the double bond, at which the reaction occurs. To distinguish the faces the descriptors Re and Si are used. The three groups attached to the carbon in double bond are first arranged in the order of their priorities based on the sequence rules. The face in which the arrangement of the highest to second highest to third highest groups is clockwise is designated as Re face and if the arrangement is anti-clockwise the face is called as Si face.

To assign:

The stereochemistry of the two chirality centres in isocitrate.

To state:

Whether the OH and H add to the Si face or Re face of the double bond.