reactions of internal acetylenes with ethylene and CO in protic solvents, e.g., ethanol, gave 3,4-disubstituted-5-ethyl-2(5H)-furanones in good yields. By using propylene or methyl acrylate instead of ethylene, small amounts of 5-n-/iso-propyl-2(5H)-furanones or 5-[2-(methoxycarbonyl)ethyl]-2(5H)-furanone were obtained.
铑羰基催化的内
乙炔与
乙烯和 CO 在质子溶剂(例如
乙醇)中的反应以良好的收率得到 3,4-二取代-5-乙基-
2(5H)-呋喃酮。通过使用
丙烯或
丙烯酸甲酯代替
乙烯,得到少量的 5-n-/异丙基-
2(5H)-呋喃酮或 5-[2-(甲氧基羰基)乙基]-
2(5H)-呋喃酮。