Diastereoselective access to hexahydro- and octahydrofuro[f]indolizines analogues of phenanthro[f]indolizidines alkaloids
作者:Fridrich Szemes、Katarı́na Kadlečı́ková、Štefan Marchalı́n、Maria Bobošı́ková、Vincent Dalla、Adam Daı̈ch
DOI:10.1016/j.tetasy.2004.04.015
日期:2004.6
ring reduction can be achieved conveniently. The resulting products 5a and 8a readily constituted platforms to access stereoselectively the partially 6a and 7a or totally 9a and 9b reduced furo[f]indolizines. The key step of the stereocontrolled reduction seems to be the catalytic hydrogenation of the furan nucleus in the (4aS,9aS)-(+)-5a product. Assignments of the absolute stereochemistry are made and
呋喃的对映体特异性合成[ ˚F ]具有不同程度的unstauration(氮茚图4a,b,图8A,图9A,和图10A),为菲的类似物[ ˚F ]吲哚里生物碱已从(完成小号) -谷氨酸在数步顺序。这是通过利用化学和催化还原方法从已知的旋光性醇-内酰胺2a和2b实现的。在这些转化过程中,我们已经表明,呋喃环的部分还原可以方便地实现。所得产品5a和8a容易构成的平台可选择性地立体选择部分6a和7a或全部9a和9b还原的呋喃[ f ]吲哚嗪酮。立体控制还原的关键步骤似乎是(4a S,9a S)-(+)- 5a产品中呋喃核的催化氢化。进行了绝对立体化学的分配,并且还讨论了这些转变的一些机理方面。