It was found that the condensation of two equivalents of 4-hydroxy-6-methyl-2H-pyran-2-one or 4-hydroxycoumarin with arylglyoxals in boiling formic acid leads to 4H-furo[3,2-c]-pyran-4-ones or 4H-furo[3,2-c]chromen-4-ones, respectively.
发现两当量的
4-羟基-6-甲基-
2H-吡喃-2-酮或
4-羟基
香豆素与芳基
乙二醛在沸腾的
甲酸中缩合生成4H-
呋喃[3,2-c]-
吡喃- 4-ones 或 4H-furo[3,2-c]chromen-4-ones,分别。