Practical AsymmetricDiels-Alder Additions to Camphor-10-sulfonic-Acid-Derived Acrylates. Preliminary Communication
作者:Wolfgang Oppolzer、Christian Chapuis、Martha J. Kelly
DOI:10.1002/hlca.19830660747
日期:1983.11.2
Starting from (+)-camphor-10-sulfonic acid (1) the chiral crystalline alcohols 3 and 11 were prepared in two steps. Lewis-acid-mediated [4+2]-additions of their acrylates to 1,3-dienes were studied. Notably, the crystalline acrylate 4 underwent TiCl2 (OiPr)2-promoted Diels-Alder addition to cyclopentadiene giving after recrystallization efficiently the pure (2R)-adduct 5.
从(+)-樟脑-10-磺酸(1)开始,分两步制备手性结晶醇3和11。研究了路易斯酸介导的丙烯酸酯向[1,3-二烯]的[4 + 2]加成反应。值得注意的是,在重结晶后,结晶的丙烯酸酯4经受了环戊二烯的TiCl 2(OiPr)2促进的Diels - Alder加成,从而有效地提供了纯的(2 R)加合物5。