THE STEREOCHEMISTRY OF ASYMMETRIC PHOSPHORUS COMPOUNDS. THE CORRELATION OF THE CONFIGURATIONS OF O-ETHYL AND O-ISOPROPYL METHYLPHOSPHONOTHIOIC ACIDS

Abstract : Methods of Melting, Chemical reactions, Dis placement reactions.)A study was made to correlate the configurations of the resolved isomers of O-isopropyl methylphosphonothioic acid and O-ethyl methylphosphonothioic acid by a physical and a chemical method. The physical method was based upon a quasi-racemate formation between dicyclohexylamine salts of the acids, the chemical method upon an alkoxide ion displacement at the asymmetric phosphorus atom of the S-methyl esters of these acids to form the common optically active ethyl isopropyl methylphosphonate. Based on the physical and the chemical evidence presented for the correlation of the configurations of O-ethyl and O-isopropyl methylphosphonothioic acid, it is concluded that the two levo enantiomorphs possess the same configuration. This conclusion agrees with that previously reached on the basis of the biochemical evidence.