I. Introduction
The influence of a chiral center on a prochiral
reaction center within the same molecule is one of
the fundamental stereochemical issues addressed in
organic synthesis. Ever since D. J. Cram1 outlined
almost 50 years ago an edifice to explain the stereoselectivity
in the addition of nucleophiles to R-chiral
carbonyl compounds, which became known as the
Cram rule,2 a fabric was created which proved to be
most fruitful in understanding, predicting, and controlling
diastereoselectivity induced by a remote
stereocenter. The aim of this review is the analysis
and comparison of the various models having evolved
on the basis of Cram’s rule and their application
toward diastereoselective synthesis.