Alkylation reactions of phosphachroman-2,4-diones and 4-hydroxy phosphacoumarins

Phosphachroman-2,4-dione and 4-alkoxyphosphacoumarin derivatives, phosphonic analogues of chromones and coumarins with potential biological activities, were synthesized in good yields through sequential base-catalyzed intramolecular cyclization of O-alkyl-O′-(2′-methoxycarbonyl phenyl)-(substituted) benzyl phosphonates and alkylation. The synthesis sets the stage for an examination of the biological activities.