Installation of 12b-substituents onto indolo[2,3- a ]quinolizidin-2-ones and application to pentacyclic alkaloid synthesis
摘要:
12b-Substituted indolo[2,3-a]quinolizidin-2-ones 5 are synthesized by treatment of Grignard reagents with O-acetyl iminium salt 4 generated by treating cyclic enaminoketone 3 with acetyl chloride. Subsequent Robinson annulation employing the Stork enamine protocol provided rac-3-phenyl-15,16-dehydroreserpone. (C) 1998 Elsevier Science Ltd. All rights reserved.