Total synthesis of dimethyl sulfomycinamate

Dimethyl sulfomycinamate (1), a methanolysis product from the natural antibiotic sulfomycin I, is synthesized in 11 steps (Scheme 19). The chemistry of various pyridine, thiazole, and oxazole heterocycles and their coupling reactions under palladium catalysis are examined. The key transformations in the synthesis are the selective palladium-catalyzed coupling reactions on doubly activated pyridine 62 and the condensation reaction between bromo ketone 69 and amide 28 to form the oxazole moiety 76. The first preparation of oxazole triflates is described, as are some of their chemical properties.