Ring expansion of 4-[(2R)-1-[(1R)-1-phenylethyl]aziridin-2-yl]butyl tosylate obtained from tosylation of 4-[(2R)-1-[(1R)-1-phenylethyl]aziridin-2-yl]butan-1-ol via formation of 1-azabicyclo[4.1.0]heptane tosylate gives substituted piperidine. The ring openings of azabicycloheptane tosylate with acetate nucleophiles proceeded in highly regio- and stereoselective manner with release of the ring-strain of the three-membered aziridine ring through the breakage of either C-N bond. This ring expansion streategy of aziridine provides a short route for asymmetric synthesis of biologically active natural alkaloid such as (R)-pipecolic acid.

Graphical abstract

中文翻译：

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从手性氮丙啶扩环反应快速高效地合成 (R)-哌啶酸

4-[(2 R )-1-[(1 R )-1-苯乙基]氮丙啶-2-基]甲苯磺酸丁酯的扩环，由 4-[(2 R )-1-[(1 R )的甲苯磺酰化得到-1-苯基乙基]氮丙啶-2-基]丁-1-醇通过形成1-氮杂双环[4.1.0]庚烷甲苯磺酸酯得到取代的哌啶。氮杂二环庚烷甲苯磺酸盐与乙酸亲核试剂的开环以高度区域和立体选择性的方式进行，通过任一CN键的断裂释放三元氮丙啶环的环张力。这种氮丙啶的扩环策略为生物活性天然生物碱如( R )-哌可酸的不对称合成提供了一条捷径。

图形概要