【摘要】 <正> 等由酮的一氰乙基化产物水解后得到的δ-酮酸,在大量乙酐或者乙酰氯存在下合成了不饱和δ-内酯.我们用4-异丁酰基庚二酸(1)在过量醋酸酐及乙酰氯存在下回流5h得到7-氧代-8,8-二甲基-△~9-六氢香豆素(2).更多还原

【Abstract】 7-Oxo-8, 8-dimethyl-△~9-hexahydrocoumarin (2) and 5-(2’-carboxyethyl)-6-isopropyl-3, 4-dihydro-a-pyrone (3) were prepared from 4-isobutyryl pimelic acid (1) by refluxing with aoctic anhydride and acetyl chloride. Reaction of 3, 3-dicyanoethyl-2, 4-hexadione with aqueous KOH yielded 3-(3’-methyl-2’, 4’-dioxocyclohexyl) propionic acid (6). 6 reacted with acetic anhydride to yield 7-oxo-8-methyl-△~8-hexahydrocoumarin (7). 7 underwent alcoholysis and amminolysis readly to give 3-(3’-methyl-2’,4’-dioxocyclohexyl)-propionic ethylester (8) and amide (9) respectively.更多还原