作者:Krzysztof B?aszczyk、Hanna Koenig、Zdzis?aw Paryzek
DOI:10.1002/ejoc.200400580
日期:2005.2
17β-(3-Oxocyclobutyl)androstane, prepared by the thermal [2 + 2] cycloaddition of dichloroketene to 3β-acetoxypregna-5,20-diene, is the key intermediate in the new, efficient synthesis of steroids bearing the 17β-butenolide fragment that characterizes cardenolides. The six-step synthesis of 3β-tert-butyldimethylsilyloxy-14α-carda-5,20(22)-dienolide was achieved with a total yield of 32%. (© Wiley-VCH
17β-(3-氧代环丁基)雄甾烷,通过二氯乙烯酮与 3β-乙酰氧基孕-5,20-二烯的热 [2+2] 环加成反应制备,是新型高效合成含有 17β-丁烯内酯片段的类固醇的关键中间体这是cardenolides的特征。3β-叔丁基二甲基甲硅烷氧基-14α-carda-5,20(22)-二烯内酯的六步合成总收率为32%。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)