Shen Jun-Wei, Qin Dong-Guang, Zhang Hong-Wang, Yao Zhu-Jun
State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
J Org Chem. 2003 Sep 19;68(19):7479-84. doi: 10.1021/jo0349328.
A new efficient synthesis of (2S,3R)-3-hydroxy-3-methylproline (3) is reported. During the course of a recent study on the Lewis acid promoted intramolecular opening of an epoxide by a carbamate NH, a highly concerted rearrangement was unexpectedly observed. Further investigations of substrate generality show that delta-carbamate-alpha,beta-epoxide esters commonly underwent similar rearrangements with the aid of Lewis acids. Retrosynthetic analysis of such a C(2)-N disconnection can lead to an efficient synthesis of (2S,3R)-3-hydroxy-3-methylproline (3) in high enantio purity. Stereochemistries were established by a Sharpless asymmetric dihydroxylation and a diastereoselective reductive amination.
报道了一种新型高效合成(2S,3R)-3-羟基-3-甲基脯氨酸(3)的方法。在最近一项关于路易斯酸促进氨基甲酸酯的NH对环氧化物进行分子内开环反应的研究过程中，意外地观察到一种高度协同的重排反应。对底物通用性的进一步研究表明，δ-氨基甲酸酯-α,β-环氧酯在路易斯酸的作用下通常会发生类似的重排反应。对这种C(2)-N断键进行逆合成分析，可以高效合成对映体纯度高的(2S,3R)-3-羟基-3-甲基脯氨酸(3)。通过夏普莱斯不对称双羟基化反应和非对映选择性还原胺化反应确定了立体化学结构。
