Sugiura M, Kobayashi S
Graduate School of Pharmaceutical Sciences, University of Tokyo, CREST, Japan Science and Technology Corporation (JST), Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Org Lett. 2001 Feb 8;3(3):477-80. doi: 10.1021/ol006990a.
[figure: see text] Ring-opening reactions of semicyclic N,O-acetals with various nucleophiles such as silyl enol ethers are effectively catalyzed by a Lewis acid (TMSOTf). Reactions of 3-substituted N,O-acetals showed high diastereoselectivities. Synthetic utility of this method has been demonstrated in the stereoselective synthesis of an anti-malarial agent, isofebrifugine.
[图:见正文] 半环状N,O-缩醛与各种亲核试剂(如硅烯醇醚)的开环反应可被路易斯酸(三甲基甲磺酸硅酯,TMSOTf)有效催化。3-取代N,O-缩醛的反应表现出高非对映选择性。该方法的合成实用性已在抗疟药异非布芬宁的立体选择性合成中得到证明。