STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES——STEREOCHEMISTRY OF ALKALINE HYDROLYSIS OF OPTICALLY ACTIVE O-ETHYL O-PHENYL PHOSPHOROTHIOIC DERIVATIVES

Abstract

The reaction of optically active O-ethyl O-phenyl phosphorochloride 1 with alcohol, phenol, amine, mercaptan or thiophenol, respectively, in the presence of an alkali obtained optically active O-ethyl O-phenyl phosphorothioic derivatives 2 with inversion of configuration. The hydrolysis of 2 was carried out in 1 N NaOH-dioxane solution. The hydrolysis of 2a and 2h predominantly gave products with inversion of configuration with OPh as leaving group, but also gave products with retention of configuration with OMe or SPr as leaving group. Exclusive products with inversion of configuration with OPh as leaving group were only obtained from the hydrolysis of 2b, 2f and 2g. The hydrolysis of 2c gave product with inversion of configuration with OC_6H_4NO_2-p as leaving group. From 2d, 2e and 2i, products with retention of configuration were formed with OC (Me)- CHCO_2 Et(Z), OC(Me)-CHCO_2Et(E) and SPh as leaving group, respectively. All the above results can be satisfactorily interpreted in the light of trigonal bipyramidal (TBP) intermediates and pseudo- rotation (BPR) concepts.