Gram-Scale, Seven-Step Total Synthesis of (-)-Colchicine.
Xiao LiangLei LiKun WeiYu-Rong YangPublished in: Organic letters (2021)
Herein we report a streamlined, gram-scale total synthesis of (-)-colchicine that takes only 7 easy steps, with an overall yield of 27-36%. To warrant the synthetic efficiency and practicality of (-)-colchicine, we tactically utilized a modified version of a powerful Ir-catalyzed amidation reported by Carreira to install the key chiral C-7 acetamido group, Suzuki and biomimetic phenol oxidative coupling, and Banwell-inspired cyclopropane ring cleavage to construct (-)-colchicine precisely and rapidly. Remarkably, a described strategy also can shorten the synthesis of allocolchicinoid to 4 steps.