The esters of phosphorus(III) acids are known to react readily with α-halocarbonyl compounds to form vinyl esters of the phosphorus(IV) acid [2, 3]. According to published data, halocyclobutanones have not been used in this reaction. In this connection, aiming to develop a synthetic approach to the phosphorus-containing cyclobutanones, we studied the reaction of 3phenyl-2,2-dichlorocyclobutanone I with the esters and amidoesters of phosphorus(III) acids. The reaction progress was monitored by tracing the amount of chloroalkanes released and also by means of TLC. It was shown that depending on the nature of the phosphorus component the reaction temperature should be varied within 80–130°С. Arylphosphonites are the most active, and amidoesters, the least active. The reaction products were purified by vacuum distillation or by column chromatography. Their structure was studied by IR, Н and Р NMR spectroscopy. By the spectral data, this reaction proceeds as the Perkov reaction [3] without the opening of the four-membered ring. DOI: 10.1134/S1070363210120224