Synthesis of the N-acetylcysteamine thioester of seco-proansamitocin.

摘要: [structure: see text] The enantioselective total synthesis of the N-acetylcysteamine thioester seco-proansamitocin, a key biosynthetic intermediate highly potent antitumor agent ansamitocin, is described, which twice utilizes Nagao acetate aldol reaction, as well an indium-mediated alkynylation benzyl bromide followed by carboalumination. step Heck reaction between two terminal alkenes for merging major fragments.