One-pot synthesis of γ-hydroxy-γ-oxaphosphonates using pentacovalent oxaphosphorane chemistry

P(V)-2,2,2-triethoxy-2,2-dihydro-5-methoxy-1,2λ5-oxaphospholene was synthesized as a new type of enolate which was hydrolyzed to give a series of phosphonates. In addition, aldol reaction of the oxaphospholene intermediate with several aldehydes as electrophiles under mild and neutral conditions produced phosphonate-containing aldol compounds through a two-step one-pot reaction.