Synthesis of New α,α-Difluoro-γ-lactones Through Intramolecular Radical Cyclization as a Key Reaction.

Abstract Carbon radicals from allyl o-trimethylsilyl-α-bromo-α,α-difluoro-acetals can cyclize onto olefines regiospecifically to give γ-lactols in good yield. These lactols have been converted to the corresponding α,α-difluoro-γ-lactones. The first synthesis of three new α,α-difluoro-γ-lactones has been accomplished.