Asymmetric Total Syntheses of Colchicine, β‑Lumicolchicine, and Allocolchicinoid <i>N</i>‑Acetylcolchinol‑<i>O</i>‑methyl Ether (NCME)
2017-08-19T00:00:00Z (GMT) by
A concise and highly enantioselective synthesis of colchicine (>99% <i>ee</i>) in eight steps and 9.3% overall yield, without the need for protecting groups, was developed. A unique Wacker oxidation was used for enabling regioselective construction of the highly oxidized and synthetic challenging tropolone C-ring. Furthermore, asymmetric syntheses of β-lumicolchicine and <i>N</i>-acetylcolchinol-<i>O</i>-methyl ether (NCME) were achieved. Notably, NCME was synthesized from β-lumicolchicine by an unusual decarbonylation and electrocyclic ring-opening cascade reaction.