A Facile Synthesis of C(3)-Alkenyl Substituted Cephems through Addition-Cyclization of Allenecarboxylates derived from Penicillin
Tanaka, H.; Kameyama, Y.; Sumida, S.-i.; Torii, S. Tetrahedron Lett. 1992, 33, 7029.
A short-cut route to cephalosporins bearing alkenyl substituents on the C(3)-position through copper(I) chloride-promoted Michael-type addition of alkernyltributyltins to allenecarboxylates, derived from penicillin, is described.