Chapter 4, Problem 48DSP

Interpretation Introduction

Interpretation:

The prochiral face of the double bond of fumaric acid to which the $\text{-OH}$ group adds to in the fumarase-catalyzed hydration of fumaric acid is to be identified.

Concept introduction:

A trigonal ${\text{sp}}^{\text{2}}$ achiral carbon atom can be transformed to the chiral carbon atom by addition of a different atom or group to the trigonal carbon atom. This carbon atom is the prochirality center.

Carbon which is bonded to three different types of atoms or groups can potentially be a prochirality center.

The two prochiral faces of a trigonal atom are enantiotopic and are designated as $\text{Re}$ and $\text{Si}$ face.

The priorities around the trigonal carbon atom are assigned on the basis of Cahn–Ingold–Prelog rules.

If decreasing priority of the other three substituents traces the clockwise path, it is designated as $\text{Re}$ face. If it traces the counterclockwise path then it is designated as $\text{Si}$ face.