Generation and Reaction of Monocarbonyliodonium Ylides: Ester Exchange of (<i>Z</i>)-(β-Acetoxyvinyl)iodonium Salts with Lithium Ethoxide and Synthesis of α,β-Epoxy Ketones
作者:Masahito Ochiai、Yutaka Kitagawa、Shinji Yamamoto
DOI:10.1021/ja971688r
日期:1997.12.1
generation of monocarbonyliodonium ylides and their alkylidene-transfer reactions to aldehydes yielding α,β-epoxy ketones. Exposure of (Z)-(2-acetoxy-1-decenyl)iodonium bromide, prepared stereoselectively by sodium acetate-catalyzed Michael addition of acetic acid to (1-decynyl)(phenyl)iodonium salt, to EtOLi in THF at −78 °C results in ester exchange to generate the monocarbonyliodonium ylide with the liberation
这里首次报道了单羰基碘鎓叶立德的产生及其亚烷基转移反应到醛,产生 α,β-环氧酮。(Z)-(2-乙酰氧基-1-癸烯基)溴化碘,通过乙酸钠催化迈克尔加成乙酸与(1-癸炔基)(苯基)碘盐的立体选择性制备,暴露于-78°THF中的EtOLi C 导致酯交换以生成单羰基碘鎓叶立德,同时释放乙酸乙酯。1H NMR 测量表明,叶立德在 THF-d8 中可稳定至 -30 °C,但在 -20 °C 时逐渐分解为 1-bromo-2-decanone。单羰基碘鎓叶立德作为羰基化合物的亚烷基转移剂,在-30°C 下与 THF-DMSO 中的醛反应得到 α,β-环氧酮,主要产物为 E-异构体。与α,β-不饱和醛,观察到羰基的选择性 1,2-加成。该叶立德的亚烷基转移反应对一系列环取代的苯甲醛的相对速率...