Wender Paul A, Hilinski Michael K, Mayweg Alexander V W
Department of Chemistry, Stanford University, Stanford, California 94305-8050, USA.
Org Lett. 2005 Jan 6;7(1):79-82. doi: 10.1021/ol047859w.
Treatment of highly potent and densely functionalized bryostatin analogue 1 with dimethyldioxirane afforded the C-9 hydroxylated hemiketal 2 via oxyfunctionalization of the C9-CH bond, one of 12 CH bonds geminal to an oxygen substituent in 1. When bryostatin analogue 3 was subjected to identical conditions, oxidation of a C-26 secondary hydroxyl group was found to compete with C-9 hydroxylation. Complete selectivity for C-9 hydroxylation was restored upon acylation of the C-26 secondary alcohol.
用二甲基二氧杂环丙烷处理高效且高度官能化的苔藓抑素类似物1，通过C9-CH键的氧官能化反应生成了C-9羟基化半缩酮2，该C9-CH键是1中与氧取代基相连的12个偕二氢原子的碳氢键之一。当苔藓抑素类似物3在相同条件下进行反应时，发现C-26仲羟基的氧化反应与C-9羟基化反应相互竞争。对C-26仲醇进行酰化后，恢复了对C-9羟基化的完全选择性。
