Fluorous-Phase Synthesis of α-Methyleneγ-lactones

Significance

Fluorous-phase organic synthesis (FPOS) was employed for the sequential Baylis-Hilman and palladium-catalyzed carbonyl allylation reactions providing a synthesis of mono- and disubstituted α-methylene-γ-lactones. The intermediates were purified by solid-phase extraction using reverse-phase fluorous silica gel (FSPE). The α-methylene-γ-lactone derivatives were formed in high cis selectivity (up to ˜100%), except for the methoxyphenyl-substituted aldehyde which led to only a slight excess of the cis diastereoisomer. Both aliphatic and aromatic aldehydes were shown to participate in the reaction although the scope was not widely investigated.