Total Synthesis of (.+-.)-Atpenin B. An Original "Clockwise" Functionalization of 2-Chloropyridine
作者:Francois Trecourt、Marc Mallet、Olivier Mongin、Guy Queguiner
DOI:10.1021/jo00100a017
日期:1994.10
(-)-Atpenin B (1) is an antibiotic produced by Penicillium sp. FO-125. The first synthesis of 2,4-dihydroxy-5,6-dimethoxy-3-((2RS,4RS)-2;4-dimethyl-1-oxohexyl)pyridine (atpenin B) (16) is reported. This molecule, which exhibits a pentasubstituted pyridine structure, was prepared from 2-chloropyridine in 13 steps, by metalating and then functionalizing, one after another, all the remaining positions of the pyridine ring. The methodology involves four metalation steps (including metalation of 2,3-dimethoxypyridine and pyridyl N,N-diisopropylcarbamates), one halogen-scrambling step, and one bromine-lithium exchange step.
(-)-天蓝色青霉素B (1) 是由Penicillium sp. FO-125产生的抗生素。2,4-二羟基-5,6-二甲氧基-3-((2RS,4RS)-2,4-二甲基-1-氧己基)吡啶(天蓝色青霉素B)(16)是首次被合成的。该化合物具有一个五取代的吡啶结构,由2-氯吡啶在13步反应后制得,依次通过金属化和官能团化,对吡啶环上的其余所有位置进行了操作。该方法涉及四个金属化步骤(包括2,3-二甲氧基吡啶和吡啶基N,N-二异丙基氨基甲酸酯的金属化)、一个卤素混排步骤和一个溴-锂交换步骤。