Chemoselective cycloadditions of 3, 4-dialkoxyfurans and alkyl coumalates. Novel loss of aromaticity of two nonbenzenoid aromatic rings in a mild thermal process

ME Jung, LJ Street, Y Usui

Index: Jung, Michael E.; Street, Leslie J.; Usui, Yoshihiro Journal of the American Chemical Society, 1986 , vol. 108, # 21 p. 6810 - 6811

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Citation Number: 25

Abstract

14 modification of the reaction conditions as follows permitted us to overcome this obstacle. Refluxing a methanol solution containing 10 equiv of lb and 1 equiv of 6b for 3 h followed by silica gel chromatography afforded an 86% yield of 13n and 13x in a ratio of 53: 47 with only a trace of 14 being produced. In addition this simple chromatography returned 86% of the unreacted coumalate Ib in pure form for use in further cycloadditions. The strutures of the ...