While the reaction of triethyl phosphonoacetate with carbonyl compounds has been well investigated, la~ c) little attention has been paid to the reaction of tetraethyl a- phosphonodicarboxylates (I) with carbonyl compounds. Wadsworth2) has reported the reaction of tetraethyl a-phosphonosuccinate with benzaldehyde to give diethyl a- benzylidenesuccinate. On the other hand, a survey of the literature has indicated that a ...