The study of racemisation rates in binaphthyls and related compounds

Abstract

This work is concerned mainly with the breakdown of the free energy of activation with the evaluation of quantities such as the energy of activation AE and entropy of activation AS of certain optically active compounds as a means of trying to understand the structural factors upon which their optical stabilities depend.The compounds studied are members of a series of 1,1-binaphthyl carhoxylic acids and esters and a peri substituted naphthalene, N-benzenesulphonyl-8-nitro-l-naphthyl glycine. Their rate coefficients of racemisation at several temperatures have been determined - those for the 1,1'-binaphthyl compounds in two solvents, aqueous sodium hydroxide and N,N-dimethyl formamide - and the results used to determine using the equations. In the experimental section the syntheses of the 1,1'-binaphthyl acids are described. The final part of this section is concerned with the preparation of optically active 1,1-binaphthyl itself on which, as yet, no measurements of rate coefficients have been made. Also described is the preparation of 2,2'-carbomethoxy-3,3-diphenic acid which was not obtained optically active.