A Biosynthetic Proposal for Ring Formation in the Antitumor Agent Halichomycin. Asymmetric Synthesis of the AB-Carbon Backbone of Halichomycin
作者:Karl J. Hale、Paschalis Dimopoulos、Maxine L. F. Cheung、Mark Frigerio、Jonathan W. Steed、Philip C. Levett
DOI:10.1021/ol017266a
日期:2002.3.1
[reaction: see text] A biosynthetic proposal for ring formation in the antitumor agent halichomycin is presented in which macrocyclization of the putative prehalichomycin intermediate 1 is the first step. Compound 2 then undergoes dehydration to the alpha-keto N-acylimine 3 followed by tandem nucleophilic addition of the C(16)-hydroxyl to form the hemimacrolactam. A stereospecific Michael ring closure