Construction of quaternary carbon centers by palladium-catalyzed intramolecular alkene insertions. Total synthesis of the Amaryllidaceae alkaloids (.+-.)-tazettine and …

MM Abelman, LE Overman, VD Tran

Index: Abelman, Matthew M.; Overman, Larry E.; Tran, Vinh D. Journal of the American Chemical Society, 1990 , vol. 112, # 19 p. 6959 - 6964

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Citation Number: 102

Abstract

Abstract: Total syntheses of (&)-tazettine (1) and (*)-6a-epipretazettine (3), which proceed in 11 steps from the known enal 7 (14 steps from commercially available pmethoxybenzyl alcohol), are reported. The pivotal step is the palladium-catalyzed cyclization of alkenyl aryl iodide 13, which proceeded in excellent yield (63-90%) and with high stereoinduction (> 20: 1) to form 14.