Synthesis of novel 4-(1-ethoxycarbonyl-methylidene)-azetidin-2-ones via a Lewis acid-catalyzed reaction of ethyl diazoacetate
作者:Gianfranco Cainelli、Paola Galletti、Massimo Gazzano、Daria Giacomini、Arianna Quintavalla
DOI:10.1016/s0040-4039(01)02108-6
日期:2002.1
Treatment of (3R,4R,1′R)-3-[1-(t-butyldimethylsilyloxy)ethyl]-4-acetoxy-azetidin-2-one with ethyl diazoacetate in the presence of a Lewis acid such as TiCl4, TiF4, AlCl3 or SnCl4 affords the novel (3S,1′R)-3-[1-(t-butyldimethylsilyloxy)ethyl]-4(1-ethoxycarbonyl-methylidene)-azetidin-2-one as an E and/or Z isomer.
(3治疗- [R,4 - [R,1' - [R)-3- [1-(吨-butyldimethylsilyloxy)乙基] -4-乙酰氧基-氮杂环丁烷-2-酮与重氮基乙酸乙酯在路易斯酸如的存在的TiCl 4,TIF 4,的AlCl 3或的SnCl 4次,得到新颖(3小号,1' - [R)-3- [1-(吨-butyldimethylsilyloxy)乙基] -4-(1-乙氧羰基亚甲基) -氮杂环丁-2-酮,为E和/或Z异构体。