Organophosphorus compounds XI: Stereochemistry of grignard displacement reactions at phosphorus in isopropyl methylphosphonohalogenates

Abstract

Abstract A series of stereospecific reactions, starting from (−)‐(isoPrO)MeP(O)H (I) (see Reaction Scheme), establishes that the absolute configuration of (+)‐(isoPrO)‐MeP(O)SMe(II) (R′=Me) is ( R ), and not ( S ) as previously suggested. The reassigned configuration is confirmed by X‐ray analysis. It follows that the displacement of X by Ph in isoPrO(Me)P(O)X proceeds with complete retention of configuration when X = SMe, but proceeds with complete inversion when X = F. In the case of X = Cl, the reaction proceeds at least predominantly with inversion of configuration.