Investigation of Steric Effects about the Amide Bond by Gas–Liquid Chromatography

Abstract

THE steric requirements of molecules dominate the rates and equilibria of many reactions in organic and inorganic chemistry. It is still difficult to make precise calculations of steric effects, but in many cases the qualitative principles controlling steric requirements have become apparent. For example, in reactions that involve addition to an unsaturated function containing a double bond, the empirical ‘rule of six’ correctly states “the greater the number of atoms in the six position, the greater will be the steric effect”¹. The rule of six has also been used to interpret conformations of polypeptides and proteins and to explain hydrolysis rates of di- and poly-peptides².