Synthesis of 3-Alkenyl-D²-cephems by Copper(I) Chloride-Promoted Alkenylation of 3-Trifluoromethylsulfonyloxy-D³-cephem with Alkenyltributyltins

Tanaka, H.; Sumida, S.-i.; Torii, S. Tetrahedron Lett. 1996, 37, 5967.

Synthesis of 3-alkenyl-D²-cephems 3 was performed in regioselective manner by copper(I) chloride-promoted alkenylation of 3-trifluoromethylsulfonyloxy-D³-cephem 1 with alkenyltributyltins. Subsequent Diels-Alder reaction of the 3-vinyl-D²-cephem 3a with acrolein opened a new access to C(2)-C(3) fused tricyclic cephalosporin 9.