Synthesis of Some Mixed Dialkyl Phosphites and their Use as Forerunners for Potential Chiral Phosphates

Abstract

Organophosphorus compounds containing a c h i d ccntrc at the P atom are of considerable interest fiom a stcreochemical point of view. Accordingly, trialkyl phosphates (RO)(RIO)(R20)P(0) (4) were synthesized starting from dialkyl phosphites. Thus: direct hydrolysis of dialkyl phosphites (ROhP(0)H (1) with tetraethylammonium hydroxide (20% aqueous solution), followed by extraction with dichloromethane affords the corresponding tetraethylammonium alkyl hydrogen phosphitcs (2). Good yields (q) of mixed dialkyl phosphites (3) were obtained on heating stoichiometric amounts of (2) and alkyl iodides in acetonitrile solution at 6O°C, for 6 hrs. Mixed dialkyl phosphites (3) were used in synthesis of some trialkyl phosphates (4) by PTC (see scheme).