Asymmetric synthesis of (+)-1-epiaustraline and attempted synthesis of australine
作者:Minyan Tang、Stephen G Pyne
DOI:10.1016/j.tet.2004.05.010
日期:2004.6
A diastereoselective synthesis of the pyrrolizidine alkaloid, (+)-1-epiaustraline has been achieved via a diastereoselective syn-dihydroxylation of a pyrrolo[1,2-c]oxazol-3-one precursor that was readily prepared by a RCM reaction. Attempts to extend this methodology to the synthesis of australine were not successful since the final pyrrolidine ring closure to produce the desired pyrrolizidine of the
通过吡咯并[1,2 - c ]恶唑-3-酮前体的非对映选择性顺式-二羟基化,可以通过RCM反应容易地制备吡咯并立啶生物碱((+)-1-epiaustraline)的非对映选择性合成。尝试将该方法扩展至合成奥曲林的尝试并未成功,因为最终的吡咯烷环闭合以产生目标分子所需的吡咯烷并没有生产力。
In order to synthesize the major C(3)-C(12) part of fostriecin, asymmetric dihydroxylation of several dienes 5a-f, prepared by cross-coupling reactions of several types. vas studied, thus providing high dependency on the hydroxyl groups at C(5) and C(l 1). The best regioselectivity was obtained with 5d to produce diol 23. which was later transformed into the advanced intermediate 26. (C) 2002 Elsevier Science Ltd. All rights reserved.