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DOI: 10.1055/s-2001-16057
Spirocyclopropane Isoxazolidines, Octahydropyrindin-4-ones and β-Lactams with Biomimetic Ethylene Release from the Electrophilic Substitution of a 1,1-Ethyleneallylzinc Complex
Publication History
Publication Date:
31 December 2001 (online)
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Electrophilic substitution of 1-ethenylcyclopropyl mesylate by 3,3-diethoxypropanal in the presence of palladium(0) (5%) and diethylzinc (2 equivalents) provided 5-cyclopropylidene-1,1-diethoxy-3-hydroxypentane; its nitrone derivatives underwent intramolecular cycloaddition to provide spirocyclopropane isoxazolidines, which then were transformed under thermal or acidic conditions, into octahydropyrindin-4-ones or bicyclic β-lactams with the ethylene phytohormone extrusion, respectively. Use of chiral auxiliaries, i.e. (l)-2-acetoxylactate can lead to enantiomerically enriched heterocycles.
palladium(0) catalysis - cyclopropylidenalkyl nitrones - intramolecular 1,3-dipolar cycloaddition - thermal ring expansion - acid induced ring contraction