A method for the stereoselective preparation of 1,2,3,6-tetrahydropyridin-3-ols and 2,3,4,7-tetrahydro-1H-azepin-3-ols, potentially versatile intermediates in the asymmetric synthesis of various piperidine alkaloids and azasugars, has been developed. The routes start with a readily available optically pure aziridine-2-carboxylate. The design strategy relies on four key transformations involving (1) stereoselective reduction of an acyl-aziridine intermediate derived from the aziridine-2-carboxylate, (2) regioselective aziridine ring opening, (3) N-allylation, and (4) ring-closing metathesis. The method developed in this investigation provides ready access to stereochemically defined and highly functionalized 3-hydroxy-substituted tetrahydropyridines and tetrahydroazepines.

中文翻译：

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由手性氮丙啶-2-羧酸酯合成四氢吡啶-3-醇和四氢氮杂-3-醇

立体选择性地制备1,2,3,6-四氢吡啶-3-醇和2,3,4,7-四氢-1 H-氮杂-3-醇的方法，是各种哌啶不对称合成中潜在的通用中间体已经开发了生物碱和氮杂糖。路线从容易获得的光学纯的氮丙啶-2-羧酸酯开始。设计策略依赖于四个关键转化，包括（1）立体选择性还原衍生自氮丙啶2-羧酸酯的酰基-氮丙啶中间体，（2）区域选择性氮丙啶环开环，（3）N-烯丙基化和（4）环-封闭复分解。在这项研究中开发的方法提供了易于获得的立体化学定义和高度官能化的3-羟基取代的四氢吡啶和四氢a庚因的方法。