The title compounds 5a-5c were prepared via the reaction of methyl 2-perfluoroalkynoates (4) with methyl 5-oxo-4-(triphenylphosphoranylidene)hex-2-enoate (3), which was obtained from the reaction of methyl propynate (...The title compounds 5a-5c were prepared via the reaction of methyl 2-perfluoroalkynoates (4) with methyl 5-oxo-4-(triphenylphosphoranylidene)hex-2-enoate (3), which was obtained from the reaction of methyl propynate (2) with acetylmethylenetriphenylphosphorane (1) at -5-0 degrees C. Intramolecular elimination of Ph(3)PO took place when compound 5 was heated in aqueous methanol at 115-120 degrees C in sealed tube, yielding dimethyl 2-trifluoromethyl-4-methylisophthalate (6a) from 5a and methyl 5-acetyl-4-hydroxy-2-heptafluoropropanylbenzoate (6b) from 5b, respectively. The structures of compounds 5, 6a and 6b were confirmed by IR, MS, H-1 NMR, F-19 NMR and C-13 NMR spectroscopy and elemental analyses. Rection mechanisms for the formation of compounds 5, 6a and 6b were proposed.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The title compounds 5a-5c were prepared via the reaction of methyl 2-perfluoroalkynoates (4) with methyl 5-oxo-4-(triphenylphosphoranylidene)hex-2-enoate (3), which was obtained from the reaction of methyl propynate (2) with acetylmethylenetriphenylphosphorane (1) at -5-0 degrees C. Intramolecular elimination of Ph(3)PO took place when compound 5 was heated in aqueous methanol at 115-120 degrees C in sealed tube, yielding dimethyl 2-trifluoromethyl-4-methylisophthalate (6a) from 5a and methyl 5-acetyl-4-hydroxy-2-heptafluoropropanylbenzoate (6b) from 5b, respectively. The structures of compounds 5, 6a and 6b were confirmed by IR, MS, H-1 NMR, F-19 NMR and C-13 NMR spectroscopy and elemental analyses. Rection mechanisms for the formation of compounds 5, 6a and 6b were proposed.
