Synthesis of BACE Inhibitor LY2886721. Part I. An Asymmetric Nitrone Cycloaddition Strategy
作者:Stanley P. Kolis、Marvin M. Hansen、Enver Arslantas、Lukas Brändli、Jonas Buser、Amy C. DeBaillie、Andrea L. Frederick、David W. Hoard、Adrienne Hollister、Dominique Huber、Thomas Kull、Ryan J. Linder、Thomas J. Martin、Rachel N. Richey、Alfred Stutz、Michael Waibel、Jeffrey A. Ward、Alexandru Zamfir
DOI:10.1021/op500351q
日期:2015.9.18
A scalable, asymmetric synthesis of (3aS,6aS)-6a-(5-bromo-2-fluorophenyl)-1-((R)-1-phenylpropyl)tetrahydro-1H,3H-furo[3,4-c]isoxazole, a key intermediate in the synthesis of LY2886721, is reported. Highlights of the synthesis include the development of an asymmetric [3 + 2] intramolecular cycloaddition facilitated by trifluoroethanol, and the development of a new synthesis of (R)-N-(1-phenylpropyl)hydroxylamine
的可扩展性,不对称合成(3如,6为)-6一个- (5-溴-2-氟苯基)-1 - (([R)-1-苯基丙基)四氢ħ,3 ħ -呋喃并[3,报道了4- c ]异恶唑,其是LY2886721合成中的关键中间体。合成的重点包括由三氟乙醇促进的不对称[3 + 2]分子内环加成反应的发展,以及新的(R)-N-(1-苯基丙基)羟胺甲苯磺酸酯合成的发展,该合成过程通过p-茴香醛亚胺,避免形成有毒的氰化氢气体副产物。合成过程分四个步骤进行,提供了36%的总收率的产品。