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T
MCCl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。