Asymmetric Synthesis of (–)-Colchicine and Its Natural Analog (–)-N-Acetylcolchicine Methyl Ether

Colchicine and its natural analogue (-)-N-acetylcolchinol methyl ether have been synthesized in a comparatively conciser asymmetric synthetic approach.Firstly, the carbon framework was constructed by Aldol condensation of simple aldehydes and ketones, and then the chiral amine intermediates were synthesized economically and efficiently through asymmetric reductive amination with chiral tert-butanesulfinamide.The 3-rings skeleton of colchicine and related alkaloids was then constructed by oxidation with hypervalent iodine reagent.Our strategy provides an efficient method for the convenient and economical synthesis of these alkaloids.