Alkylation of cyclic beta-oxophosphonates using the ion pair extractiv
e-phase transfer catalysis method was studied using 2-(diethoxyphosphi
nyl)cyclohexanone as the model compound. Unlike related phosphonic aci
d derivatives, the cyclic beta-oxophosphonates exhibited ambident char
acter under phase transfer conditions when dichloromethane was used as
the solvent. Carbon alkylation was most effective when activated and
sterically less demanding alkyl halides were utilized.