Hyperireflexolides A 和 B 通过简单的酰基间苯三酚起始材料的脱芳构化和断裂分六个步骤合成。脱芳构酰基间苯三酚经历一系列氧化自由基环化、逆迪克曼断裂、立体发散分子内羰基烯反应以及最终的α-羟基-β-二酮重排,得到目标天然产物。该序列基于一项生物合成提议,该提议声称 hyperireflexolides 是高度重排的多环聚异戊二烯酰基间苯三酚 (PPAP),该提议得到了 hyperireflexolides B 结构修改的支持。
Solid phase synthesis of 1,5-disubstituted pyrazole-4-hydroxamic acids and pyrazole-4-carboxamides via direct amidation of β-ketoesters
作者:Weixu Zhai、Samuel W. Gerritz、Michael J. Sofia
DOI:10.1016/j.tetlet.2011.11.031
日期:2012.1
This manuscript describes a convenient method for the directamidation of methyl and ethyl β-ketoesters to generate solid-supported β-ketohydroxamates or β-ketoamides and the application of this methodology to the synthesis of 1,5-disubstituted pyrazole-4-hydroxamic acids and pyrazole-4-carboxamides.