The synthesis of P-chiral optically pure phosphorothioates,phosphorotrithioates, phosphoroselenothioates,methanephosphonothioates, and methylphenylphosphinothioates

Enantiomers of representative alkyl esters of phosphorothioic ( 7 ), phosphorodithioic ( 6 ), phosphorotrithioic ( 11 ), phosphoroselenothioic ( 9 ), methanephosphonothioic ( 28 ), methanephosphonodithioic ( 25 ), and methylphenylphosphinothioic ( 31 ) acids were prepared from corresponding pure diastereoisomers of N-R(+)- or S(-)-α-methylbenzyl] phosphamidochalcogenates (e.g. 2 , 3 , 12 , 17 , 23 , 26 , and 30 ) via PN → PX conversion, which has been proved to proceed with full retention of configuration at phosphorus.