Fragmentation-Related Phosphonylation of Nucleophiles Utilizing P-Alkyl 2,3-oxaphosphabicyclo[2.2.2]octene 3-oxide Precursors

New P-alkyl 2,3-oxaphosphabicyclo-[2.2.2]octene 3-oxides were synthesized by the Bayer-Villiger oxidation of the corresponding 7-phosphanorbornene 7-oxides and were used as precursors for reactive alkylmetaphosphonates useful in the phosphonylation of alcohols. This is the first case that the reactivity of the two regioisomers formed by O-insertion was differentiated and that the fragmentation-related phosphonylation leading to phosphonic acid-esters was achieved under microwave-assisted conditions.