Convenient procedure for the stereospecific synthesis of optically active alkyl S-alkyl methylphosphonothioates, dialkyl S-alkyl phosphorothioates, dialkyl methylphosphonates, and trialkyl phosphates
作者:David B. Cooper、C. Richard Hall、Thomas D. Inch
DOI:10.1039/c39750000721
日期:——
Starting from the opticallyactive cyclic esters prepared from ephedrine and RPSCl2(R = Cl or Me), opticallyactive alkyl S-methyl methylphosphonothioates and dialkyl S-methyl phosphorothioates are isolated in yields of 32–60%, by a sequence which permits the assignment of absolute configuration to the products; bromine promoted methanolysis of the S–Me derivatives affords the corresponding O-methyl
Stereospecific synthesis from carbohydrate precurors of (R)- and (S)-ethyl isopropyl methyl phosphate and other optically active neutral phosphorus esters
作者:C. Richard Hall、Thomas D. Inch、Gilbert J. Lewis、Rosemary A. Chittenden
DOI:10.1039/c39750000720
日期:——
Stereospecific syntheses starting from carbo-hydrate precursors of (+)-(R) and (–)-(S)-ethyl iso-propyl methyl phosphates, (+)-(R)-O-ethyl O,S-dimethyl phosphorothioate, and (+)-(R)-ethyl methyl methyl-phosphonate are described; the enantiomeric purity of these compounds was determined by an n.m.r. method involving the use of tris-[3-(heptafluoro-n-propylhydroxy-methylene)-(+)-camphorato]europium(III)