AsymmetricDiels-Alder Reactions of Cyclopentadiene withN-Crotonoyl- andN-Acryloyl-4,4-Dimethyl-1,3-Oxazolidin-2-one, Mediated by ChiralLewis Acids
作者:Christian Chapuis、Janusz Jurczak
DOI:10.1002/hlca.19870700223
日期:1987.3.18
One-pot Diels-Alder reactions of cyclopentadiene with 3-crotonoyl- (2) and 3-acryloyl-4,4-dimethyl-1,3-oxazolidin-2-one (3), Mediated by chiral Lewis acids, are described. AlCl3, EtAlCl2, Et2AlCl, TiCl4, ZrCl4, SnCl4, SiCl4, and BBr3, modified with derivatives of D-mannitol, L-tartaric acid, and (R)-binaphthol, were applied as chiral promotors. The reaction with dienophile 2, carried out in CH2Cl2
描述了由手性路易斯酸介导的一锅迪尔斯-环戊二烯与3-巴豆酰基- (2)和3-丙烯酰基-4,4-二甲基-1,3-恶唑烷-2-酮(3)的Alder反应。以D-甘露醇,L-酒石酸和(R)-联萘酚的衍生物改性的AlCl 3,EtAlCl 2,Et 2 AlCl,TiCl 4,ZrCl 4,SnCl 4,SiCl 4和BBr 3用作手性促进者。与亲二烯体2的反应,在CH 2 Cl 2中进行在-78°下以高收率表征了优异的π面选择性。在与亲双烯体3反应的情况下,手性转移的效率低得多。