Enantiospecific Syntheses of Valienamine and 2-<i>e</i><i>pi</i>-Valienamine<sup>1</sup>
作者:Tony K. M. Shing、Tin Y. Li、Stanton H.-L. Kok
DOI:10.1021/jo982024i
日期:1999.3.1
Cyclic sulfite 10, readily available from (-)-quinic acid (3) in 10 steps, was ring opened regio- and stereospecifically with azide anion to give (1S,2R,3R,4R)-1-azido-3,4-di-O-benzyl-5-(benzyloxymethyl)cyclohex-5-ene-2,3,4-triol (11). Deprotection of 11 afforded, for the first time, 2-epi-valienamine (2), which was isolated as penta-N,O-acetyl-2-epi-valienamine (14). The configuration of the free
可以从10个步骤轻松从(-)-奎宁酸(3)中获得的环状亚硫酸盐10,与叠氮化物阴离子在区域和立体上进行开环反应,得到(1S,2R,3R,4R)-1-叠氮基-3,4-二-O-苄基-5-(苄氧基甲基)环己基-5-烯-2,3,4-三醇(11)。11的脱保护作用首次得到2-表-缬氨酸胺(2),其被分离为五-N,O-乙酰基-2-表-缬氨酸胺(14)。通过两个步骤将11中的游离羟基的构型颠倒,以得到被保护的瓦伦胺19,其被脱保护以得到瓦伦胺(1),分离为五-N,O-乙酰基瓦伦胺(21)。该方法分16步(总产率为7%)提供了(+)-戊烯胺(1),并分13步(总产率为11%)记录了2-表戊烯胺(2)的首次合成。