New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement-Cuprate Cross-Coupling
作者:Karsten Krohn、Dietmar Gehle、Ulrich Flörke
DOI:10.1002/ejoc.200500151
日期:2005.7
The alkylated allyl alcohols 6a, 7, and 8 (R = Me, Et, nBu) were formed in the reaction of the Cerný epoxide 3 with the Cyano–Gilman cuprates. The one-pot reaction was initiated by base-catalyzed epoxide allyl alcohol rearrangement to compound 5, followed by unprecedented vinyl tosylate cross-coupling with the cuprates, to form the alkylation products 6a, 7, and 8. The allyl alcohol 6a was transformed
烷基化烯丙醇 6a、7 和 8(R = Me、Et、nBu)是在 Cerný 环氧化物 3 与氰基-吉尔曼铜酸盐的反应中形成的。一锅反应由碱催化环氧化物烯丙醇重排为化合物 5 引发,随后甲苯磺酸乙烯酯与铜酸盐发生前所未有的交叉偶联,形成烷基化产物 6a、7 和 8。烯丙醇 6a 转化为许多新的支链 1,6-脱水糖在一系列高度立体选择性反应中。这些产品与大多数已知的 Cerný 环氧化物衍生物在立体化学上是互补的,可用作聚丙酸酯衍生的天然产品的手性结构单元。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)