1991 年 39 巻 5 号 p. 1298-1301
The reaction of homophthalic anhydride (1) and aldehydes in the presence of a strong base was studied. Reaction of 1 and benzaldehyde in the presence of NaH in anhydrous tetrahydrofuran (THF) at low temperature (0°C-room temperature) followed by treatment with diazomethane gave the cycloadduct, trans-4-methoxycarbonyl-3-phenyl-3, 4-dihydrocoumarin, and the reaction at 50°C gave, after similar work-up, the C-4 methylene condensed product, methyl 2-(2-methoxycarbonylphenyl)-3-phenylacrylate, selectively. Treatment of homophthalic anhydride having a terminal aldehyde group in the side chain at the C-4 position with NaH in anhydrous THF at low temperature resulted in intramolecular cycloaddition in fair yield.
