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[摘要]：An efficient synthesis of 3-bromoacetyl-4-hydroxy-6-methyl-2H-pyran-2-one by bromination of dehydroacetic acid in glacial acetic acid is described. Novel 4-hydroxy-6-methyl-3-(2-substituted-thiazol-4-yl)-2H-pyran-2-ones have been prepared from the reaction of 3-bromoacetyl-4-hydroxy-6-methyl-2H-pyran-2-one with thioamides, thiourea, and diphenylthiocarbazone. The condensation reaction of 6-methyl-4H-furo[3,2c]pyran-3,4-dione, obtained from the reaction of 3-bromoacetyl-4-hydroxy-6-methyl-2H-pyran-2-one with aliphatic amines, with benzaldehydes and acetophenones led to novel 2-ary-lidene-6-methyl-2H-furo[3,2-c]pyran-3,4-diones and 6-(2-arylprop-1-enyl)-2H-furo[3,2-c]pyran-3,4-diones. The structure of all compounds was established by elemental analysis, IR, NMR, and mass spectra. |
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