Cycloadditions. Part III. Steric effects in the addition of 2-diazopropane to conjugated allenic esters and nitriles

SD Andrews, AC Day, RN Inwood

文献索引：Andrews,S.D. et al. Journal of the Chemical Society [Section] C: Organic, 1969 , p. 2443 - 2449

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被引用次数: 8

摘要

Esters of buta-2-, 3-dienoic acid and its methyl-substituted analogues react with 2- diazopropane at more electrophilic (αβ) double-bond, but the orientation of addition is dependent on the degree of substitution at the γ-carbon atom. Allenes monosubstituted or unsubstituted at the γ-position give 4-alkylidene-1-pyrazolines (ie the electronically preferred adducts). The initial adduct from methyl buta-2, 3-dienoate isomerises under the ...