Direct asymmetric synthesis of quaternary carbon centers by the addition-elimination process: nitroolefination of. alpha.-substituted. delta.-lactones

…, M Node, H Nagasawa, Y Naniwa, T Taga…

Index: Fuji, Kaoru; Node, Manabu; Nagasawa, Hideko; Naniwa, Yoshimitsu; Taga, Tooru; et al. Journal of the American Chemical Society, 1989 , vol. 111, # 20 p. 7921 - 7925

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Citation Number: 38

Abstract

Abstract: The reactions of chiral nitro enamines 2a-c with zinc enolates 4-6 of a-substituted &lactones afforded a, a-disubstituted &lactones with a high ee through an addition- elimination process. The best results were obtained with the reaction of 2c with 5. Michael- type addition of the enolate onto the nitro enamine is kinetically controlled and decides the absolute stereochemistry of the product. A cyclic transition model is proposed to ...