Efficient Asymmetric Synthesis of (2R,3R)-3-{(1R)-1-[tert-Butyl(dimethyl)-siloxy]ethyl}-4-oxoazetidin-2-yl Acetate
作者:Fen-Er Chen、Hui-Fang Dai、Jian-Ping Huang、Lei Zhao、Shuang-Xi Gu、Zhong-Hua Wang、Hao Zhang
DOI:10.1055/s-0030-1258407
日期:2011.2
(2R,3R)-3-(1R)-1-[tert-Butyl(dimethyl)siloxy]ethyl}-4-oxoazetidin-2-yl acetate was efficiently prepared from l-ascorbic acid. The key steps were the a highly diastereoselective [2 + 2] cycloaddition of diketene with an (S)-glyceraldehyde-derived aldimine to give the ketone, stereoselective titanium tetrachloride mediated asymmetric reduction to give the corrsponding S-configured alcohol, and Mitsunobu
由1-抗坏血酸有效地制备了(2 R,3 R)-3-(1 R)-1- [叔丁基(二甲基)甲硅烷氧基]乙基} -4-氧杂玉米ti丁-2-基乙酸酯。关键步骤是双烯酮与(S)-甘油醛衍生的醛亚胺的高度非对映选择性[2 + 2]环加成生成酮,立体选择性四氯化钛介导的不对称还原生成相应的S-构型醇和Mitsunobu转化后者得到所需的R-构型的醇。 碳青霉烯-戊烯-杂环-环加成-环化