Synthesis of Leprapinic Acid, Calycine and Analogues by Sequential “[3+2] Cyclization/Suzuki/Lactonization” Reactions
作者:Zafar Ahmed、Uwe Albrecht、Peter Langer
DOI:10.1002/ejoc.200500142
日期:2005.8
cyclization of 1,3-dicarbonyl dianions or 1,3-bis(silyl enol ether)s with oxalyl derivatives – and subsequent boron tribromide-mediated lactonization. Leprapinic acid was prepared by chemoselective boron tribromide-mediated deprotection of permethylated leprapinic acid. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
花萼和类似物是在 γ-亚烷基-α-羟基丁烯内酯的 Suzuki 交叉偶联反应的基础上制备的 - 通过 1,3-二羰基二价阴离子或 1,3-双(甲硅烷基烯醇醚)与草酰衍生物的环化很容易获得 -以及随后的三溴化硼介导的内酯化。Leprapinic 酸是通过化学选择性三溴化硼介导的全甲基化 Leprapinic 酸的脱保护制备的。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)