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Efficient Intramolecular Cyclizations of Phenoxyethynyl Diols into Multisubstituted α,β-Unsaturated Lactones

Masahiro Egi*, Yuya Ota, Yuka Nishimura, Kaori Shimizu, Kenji Azechi and Shuji Akai

*School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, Shizuoka 422-8526, Japan, Email:

M. Egi, Y. Ota, Y. Nishimura, K. Shimizu, K. Azechi, S. Akai, Org. Lett., 2013, 15, 4150-4153.

DOI: 10.1021/ol401824v

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An AgOTf-catalyzed intramolecular cyclization of phenoxyethynyl diols affords multisubstituted α,β-unsaturated-γ-lactones in good yields under mild conditions. This method was also applicable to the synthesis of α,β-unsaturated-δ-lactones. Replacement of AgOTf with a stoichiometric amount of N-bromosuccinimide furnishes α-bromo-substituted α,β-unsaturated lactones.

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Key Words

butenolides, 5,6-dihydropyran-2-ones

ID: J54-Y2013