A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: a formal synthesis of (S)-coniine from l-norvaline
作者:Abdullah Karanfil、Berrin Balta、Mustafa Eskici
DOI:10.1016/j.tet.2012.09.081
日期:2012.12
β-unsaturated esters after acidic hydrolysis. Hydrogenation of the unsaturated esters and subsequent thermal cyclization afforded the related alkyl substituted piperidine-2-ones. This approach represents a novel [3+3] cyclization strategy for the asymmetric synthesis of alkyl substituted piperidin-2-ones. Efficiency of the cyclization process is illustrated by a formal asymmetric synthesis of (S)-coniine from l-norvaline
一组代表性的1,2-环氨基磺酸盐与原丙酸三乙酯的区域选择性开环反应在酸性水解后有效地进行,以递送相应的δ-氨基-α,β-不饱和酯。不饱和酯的氢化和随后的热环化提供了相关的烷基取代的哌啶-2-酮。这种方法代表了一种新的[3 + 3]环化策略,用于烷基取代的哌啶-2-酮的不对称合成。由1-正缬氨酸的形式不对称合成(S)-丝氨酸说明了环化过程的效率。