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Intramolecular Conjugate Ene Reaction of γ-Difluoromethyl- and γ-Trifluoromethyl-α,β-Unsaturated γ-Butyrolactones. | LitMetric

Intramolecular Conjugate Ene Reaction of γ-Difluoromethyl- and γ-Trifluoromethyl-α,β-Unsaturated γ-Butyrolactones.

J Org Chem

Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.

Published: November 2015

A general synthetic strategy to cis-fused bicyclic γ-butyrolactones via the retro-Diels-Alder reaction/intramolecular conjugate ene cascade (RDA/ICE) reaction under the flash-vacuum pyrolysis of maleic anhydride adducts is developed. The reaction gave high yields of products with high stereoselectivity. The existence of the difluoromethyl or trifluoromethyl group at the γ-position of the in situ-generated homoalkenyl- or homoalkynyl-α,β-unsaturated γ-butyrolactones was found to accelerate the rate of the intramolecular conjugate ene reaction leading to γ-difluoromethylated and γ-trifluoromethylated cis-fused bicyclic γ-butyrolactones.

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Source
http://dx.doi.org/10.1021/acs.joc.5b01562DOI Listing

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