Enantioselective Synthesis of the C1−C11 Fragment of Bafilomycin A<sub>1</sub> Using Non-Wittig and Desymmetrization Strategies
作者:Jean-Christophe Poupon、Emmanuel Demont、Joëlle Prunet、Jean-Pierre Férézou
DOI:10.1021/jo034018e
日期:2003.6.1
excellent enantioselectivity. Further elaboration led to C5-C11 aldehyde 24, which was coupled with sulfone 3 to give lactone 25 in very good yield. The subsequent reductive elimination created the E-trisubstituted C4-C5 olefin with a 13:1 selectivity. The E C2-C3 double bond was then installed by methanol elimination, and compound 33 was obtained after a few functional group manipulations and a Negishi
合成了bafilomycin A(1)的C1-C11片段33。从4-氧肟酸酯13分六个步骤制备中间体酮16。先用Koga手性碱对该酮进行不对称化,然后用TMCCl淬灭,提供具有优异对映选择性的甲硅烷基烯醇醚17。进一步精制得到C5-C11醛24,其与砜3偶联以非常好的收率得到内酯25。随后的还原消除产生具有13:1选择性的E-三取代的C4-C5烯烃。然后通过消除甲醇来建立EC 2 -C 3双键,并且在几次官能团处理和Negishi甲基锆化之后,获得化合物33。