Synthesis and reactions of 1,3-dicarbonyl-substituted troponoids: Conversion to tropolones having an isoxazole or a pyrazole ring
作者:Tomoyuki Nasu、Tomoko Tagawa、Kimiaki Imafuku
DOI:10.1002/jhet.5570350222
日期:1998.3
out to give troponoids possessing an isoxazole or a pyrazole ring. The parent compounds, 3-(3-pyrazolyl)tropolone (13) and 3-(1-methylpyrazol-3-yl)tropolone (21), were obtained via hydrolysis and decarboxylation. Similarly, 2-ethoxycarbonyl-4,9-dihydrocyclohepta[b]pyran-4,9-dione (3) reacted with hydroxylamine, hydrazine, and methylhydrazine to yield troponoids possessing a heterocyclic ring.
在乙氧基钠存在下,用草酸二乙酯处理3-乙酰基对羟基苯甲酸酯(1),得到次要产物3-(2-乙醛基-1-氧代乙基)Tropolone(2)及其环化的2-乙氧基羰基-4,9-二氢环己酮[ b ] pyran-4,9-dione(3)为主要化合物。前者很容易转换为后者。然后,作为带有1,3-二羰基的稳定的合成子,制备了2-(2-乙氧基--1-氧乙基)-7-甲基氨基tropone(5)。进行化合物5与羟胺,肼和甲基肼的反应,得到具有异恶唑或吡唑环的类肌钙体。母体化合物3-(3-吡唑基)tropolone(13)和3-(1-甲基吡唑-3-基)大麦酚酮(21),是通过水解和脱羧获得的。类似地,2-乙氧基羰基-4,9-二氢环庚[ b ]吡喃-4,9-二酮(3)与羟胺,肼和甲基肼反应以产生具有杂环的类肌钙体。