Synthesis of C1–C20 and C21–C40 fragments of tetrafibricin
摘要:
Efficient syntheses of suitably functionalized top and bottom fragments of tetrafibricin are described. The bottom fragment is prepared by two consecutive Kocienski-Julia couplings, while the top fragment synthesis features a dithiane alkylation and a Horner-Wadsworth-Emmons reaction. (C) 2011 Elsevier Ltd. All rights reserved.
Stereoselective synthesis of two possible diastereomers of (−)-gummiferol was accomplished by the stepwise epoxidation and Cadiot–Chodkiewicz reaction as the key transformations. Detailed comparison of their 1H and 13C NMR data and specific rotation with those of the natural product led to the absolute structural elucidation of (−)-gummiferol.
(-)-gummiferol的两种可能的非对映异构体的立体选择性合成是通过逐步环氧化和Cadiot-Chodkiewicz反应作为关键转化来完成的。他们的1 H和13 C NMR数据以及比旋光度与天然产物的详细比对导致(-)-gummiferol的绝对结构阐明。