Asymmetric glycolate aldol reactions using cinchonium phase-transfer catalysts
Asymmetric glycolate aldol reactions using cinchonium phase-transfer catalysts
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DOI：
10.1021/ol051096a
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发表时间：
2005-09-01
期刊：
影响因子：
5.2
通讯作者：
Cannon, JF
中科院分区：
文献类型：
--
作者：
Andrus, MB;Liu, J;Cannon, JF
金鸡纳相转移催化剂（PTC）被开发用于乙醇酸羟醛缩合反应，以得到差异保护的1，2-二醇产物。甲硅烷基烯醇醚9反应生成二苯甲基保护的产物。O-烯丙基三氟苄基金鸡纳鎓氢氟化物CN-4（20 mol %）催化9与苯甲醛加成得到单一合成产物8，产率76%，ee值80%，产物经重结晶富集至95% ee，产物经Baeyer-Villiger反应转化为有用的酯中间体。
Cinchona phase-transfer catalysts (PTC) were developed for glycolate aldol reactions to give differentially protected 1,2-diol products. Silyl enol ether 9 reacted to generate benzhydryl-protected products. O-Allyl trifluorobenzyl cinchonium hydrofluoride CN-4 (20 mol %) catalyzed the addition of 9 to benzaldehyde to give 8 as a single syn-product in 76% yield and 80% ee. Recrystallization enriched the product to 95% ee, and a Baeyer-Villiger reaction transformed the product into useful ester intermediates.