Lewis acid-catalyzed ring-opening reactions of semicyclic N,O-acetals.
[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.
Sugiura
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M
Graduate School of Pharmaceutical Sciences, University of Tokyo, CREST, Japan Science and Technology Corporation (JST), Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Kobayashi
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S