Ring-closing metathesis and palladium-catalyzed formate reduction to 3-methyleneoxepanes. Formal synthesis of (−)-zoapatanol
作者:Hsiu-Yi Cheng、Yu-Shiang Lin、Chong-Si Sun、Ting-Wen Shih、Hui-Hsu Gavin Tsai、Duen-Ren Hou
DOI:10.1016/j.tet.2011.10.023
日期:2012.1
A sequence of ring-closing metathesis and palladium-catalyzed formate reduction was developed for preparing O-heterocycles with an exocyclic olefin and applied to the asymmetric synthesis of zoapatanol. The key vicinal stereocenters in zoapatanol were constructed from the L-malic acid-derived lactone by successive chelation-controlled addition of alkyl groups. The O-allylations to prepare the dienes for RCM were achieved with the tertiary alcohols bearing internal olefins. The ring opening of oxepane, a new reaction pathway for the Pd-formate reduction, is also reported. (C) 2011 Elsevier Ltd. All rights reserved.