Heteroatomic chains and their products of cyclisation. IV. t??butyl??2??phthalimido??2??(3, 6??dihydro??1, 3??2H??thiazine??2??yliden)??acetates substituted in position 5 by a …
G Duguay, JP Guémas, JC Meslin…
文献索引：Duguay; Guemas; Meslin; et al. Journal of Heterocyclic Chemistry, 1980 , vol. 17, # 4 p. 767 - 770
Abstract Substituted N′-thioacetylformamidines, readily enthiolized, exist in fact in the form of zwitterions 8 with the transfer of the mobile hydrogen on the nitrogen N′. These zwitterions under (4+ 2) cyclocondensation with dienophiles. The dihydrothiazines formed (10) are possible interesting intermediates in the synthesis of cephems and cephalosporin analogs.
