Pyrrolizidine Alkaloids. The Synthesis and Absolute Configuration of All Stereoisomers of 4-Carboxy-4-ethyl-3-hydroxy-2-isopropyl-4-butanolide, the Necic Acid …

T Matsumoto, H Terao, N Ishizuka, S Usui…

文献索引：Matsumoto; Terao; Ishizuka; Usui; Nozaki Bulletin of the Chemical Society of Japan, 1992 , vol. 65, # 7 p. 1761 - 1770

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被引用次数: 2

摘要

All stereoisomers (4a, b–7a, b) of 4-carboxy-4-ethyl-3-hydroxy-2-isopropyl-4-butanolide, the necic acid component of axillaridine, have been synthesized. Methyl (E)-(S)-(+)-2-ethyl-4- methoxycarbonyl-5-methyl-2-hexenoate (12a) was converted into γ-lactone acids, 4a (2S, 3S, 4S), 5a (2S, 3R, 4R), and 5b (2R, 3S, 4S), by a series of reactions: Epoxidation with m- chloroperbenzoic acid, treatment with acetone in the presence of tin (IV) chloride, acidic ...