The phosphorus trichloride–oxygen–olefin reaction: conformation and elimination studies on products derived from 1-chloro-2-fluoro- and 1,2-difluoro-ethylene

Abstract

The reaction of phosphorus trichloride and oxygen with fluoro-olefins gives mixtures containing phosphoric and phosphonic dichlorides together with C–C cleavage products. In a wide range of compounds of the type (RO)₂P-(O)·CHX·CHYCl, including products derived from these reactions, elimination of HCl occurs stereospecifically or stereoselectively, and in the case of pairs of diastereoisomers stereoconvergently, to give the olefins (RO)₂P(O)-CXCHY with X and Y cis. Suggestions are made concerning correlation of ground state conformational properties determined by ¹H and ¹⁹F n.m.r. studies, with observed mode of HCl elimination.