The Journal of organic chemistry

Asymmetric synthesis of the protoberberine alkaloid (S)-(-)-xylopinine using enantiopure sulfinimines

FA Davis, PK Mohanty

Index: Davis, Franklin A.; Mohanty, Pradyumna K. Journal of Organic Chemistry, 2002 , vol. 67, # 4 p. 1290 - 1296

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Citation Number: 62

Abstract

A concise enantioselective synthesis of (S)-(-)-xylopinine (1) is described involving the addition of the laterally lithiated derivative of o-tolunitrile of 16 to enantiopure sulfinimine (+)- 14. Treatment of the resulting cyano sulfinamide adduct (-)-17b with DIBAL-H accomplishes five operations in a single pot and furnishes the cyclic imine (+)-18 in good yield. Reduction and cyclization affords (S)-(-)-1. Alternatively basic hydrolysis of 17b, c gives isoquinolone ...