Direct synthesis of α-substituted phosphonates

The α-substituted phosphonates (OCH2CMe2CH2O)P(O)CH(X)(Ar) [X=Cl, OMe, NMe2 and OSiMe3], useful precursors for Horner–Wadsworth–Emmons reactions, are readily prepared by treating (OCH2CMe2CH2O)PX with an aromatic aldehyde. In the reaction of (OCH2CMe2CH2O)PCl with furfuraldehyde and cinnamaldehyde, the 5-chlorofurfurylphosphonate (OCH2CMe2CH2O)P(O)CH2(5-Cl-C4H2O) and the γ-chlorophosphonate (OCH2CMe2CH2O)P(O)CHCH-CH(Cl)Ph, respectively, are formed in good yields.