Oxidative Cyclization of β,γ-Unsaturated Carboxylic Acids Using Hypervalent Iodine Reagents: An Efficient Synthesis of 4-Substituted Furan-2-ones
Kensuke Kiyokawa*, Kenta Takemoto, Shunsuke Yahata, Takumi Kojima, Satoshi Minakata*
*Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan, Email: kiyokawachem.eng.osaka-u.ac.jp, minakatachem.eng.osaka-u.ac.jp
K. Kiyokawa, K. Takemoto, S. Yahata, T. Kojima, S. Minakata, Synthesis, 2017, 49, 2907-2912.
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An oxidative cyclization of β-substituted β,γ-unsaturated carboxylic acids using a hypervalent iodine reagent provides 4-substituted furan-2-ones. The use of the highly electrophilic PhI(OTf)2, which is in situ prepared from PhI(OAc)2 and Me3SiOTf, is crucial. Depending on the substitution pattern at the α-position of the substrates, furan-2(5H)-ones or furan-2(3H)-ones are produced.
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