the preparation of diverse and fairly complex structures bearing the bisphosphonate moiety, which belong to a group of pharmacologically important compounds. The use of tetraethyl vinylidenebisphosphonate as a dipolarophile in 1,3-dipolarcycloaddition reactions was investigated. In particular, the cycloaddition reactions between tetraethyl vinylidenebisphosphonate and azides and nitrileoxides, and