19-Deformyl-4'-deoxydesmycosin (TMC-016): synthesis and biological properties of a unique 16-membered macrolide antibiotic.

19-Deformyl-4'-deoxydesmycosin was synthesized by the following synthetic route: 19-Deformylation of desmycosin, 3,2',4''-tri-O-trimethylsilylation, 4'-O-sulfonylation, 4'-iodination, reductive deiodination and 3,2',4''-tri-O-detrimethylsilylation. Deformylation of the aldehyde group at the C-19 position was achieved by two different methods: A) A simple one-step deformylation using Wilkinson's catalyst ((Ph3P)3RhCl). B) Reductive decarboxylation of the 19-carboxyl derivative following NaClO2 oxidation of the aldehyde. 19-Deformyl-4'-deoxydesmycosin showed very strong antimicrobial activity in vitro and in vivo.