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Highly substituted cyclic β-alkoxyvinyl phosphonates underwent thermal [2+2] cycloaddition with activated ketenes to afford bicyclic phosphonates. Fragmentation of the central polarized bond of this bicyclic system occurred readily upon treatment with zinc in acetic acid, to give rise to ring expanded products. This method provides access to cycloheptane-1,3-diones substituted at the 4-position with a phosphonate group.

The reaction of ketophosphonium ylides with dimethyl acetylenedicarboxylate in aprotic solvents gave mixtures of Z and E alkene products. Under protic conditions the initial Michael adduct was protonated and gave Z and E isomers of the alkene product as well. Depending on the alkyl group of the ketoylide, different product ratios were seen.

Alkylation of cyclic β-oxophosphonates using the ion pair extractive-phase transfer catalysis method was studied using 2-(diethoxyphosphinyl)cyclohexanone as the model compound. Unlike related phosphonic acid derivatives, the cyclic β-oxophosphonates exhibited ambident character 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

The reaction of ketophosphonium ylides with dimethyl acetylenedicarboxylate in aprotic solvents gave mixtures of Z and E alkene products. Under protic conditions the initial Michael adduct was protonated and gave Z and E isomers of the alkene product as well. Depending on the alkyl group of the ketoylide, different product ratios were seen.

Michael reaction of phosphonate stabilized anions with activated alkenes and alkynes results in 1,4-addition, diastereoselective Robinson annulation, or (n+ 2) ring enlargement reactions.

A variety of β-alkoxyvinylphosphonium bromides were prepared and reacted with sodium ethoxide and dimsyl anion to generate good yields of phosphine oxides 3 rather than the previously reported ylide 4.

Alkylation of cyclic β-oxophosphonates using the ion pair extractive-phase transfer catalysis method was studied using 2-(diethoxyphosphinyl)cyclohexanone as the model compound. Unlike related phosphonic acid derivatives, the cyclic β-oxophosphonates exhibited ambident character 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

Highly substituted cyclic β-alkoxyvinyl phosphonates underwent thermal [2+2] cycloaddition with activated ketenes to afford bicyclic phosphonates. Fragmentation of the central polarized bond of this bicyclic system occurred readily upon treatment with zinc in acetic acid, to give rise to ring expanded products. This method provides access to cycloheptane-1,3-diones substituted at the 4-position with a phosphonate group.

Michael reaction of phosphonate stabilized anions with activated alkenes and alkynes results in 1,4-addition, diastereoselective Robinson annulation, or (n+ 2) ring enlargement reactions.