A Simple and Convenient Synthesis of 5-Alkyl-Substituted 3-Isopropenyl- and 3-Acetyltropolones
作者:Kimiaki Imafuku、Kiyomi Arai
DOI:10.1055/s-1989-27300
日期:——
2-Alkyl-substituted 6,6-dimethylfulvenes 3a-d, prepared by alkaline condensation of alkylcyclopentadienes 2a-d with acetone, react with dichloroketene to give 2-alkyl-substituted 7,7-dichloro-4-isopropyl-idenebicyclo[3.2.0]hept-2-en-6-ones 4a-d. The cycloadducts 4a-d are hydrolyzed in aqueous acetic acid in the presence of sodium acetate to give 5-alkyl-substituted 3-isopropenyltropolones (2-hydroxy-3-isopropenyl-2,4,6-cycloheptatrienones) 5a-d. These 3-isopropenyltropolones 5a-d are hydrogenated on 5% palladium-charcoal to afford 5-alkyl-3-isopropyltropolones 6a-d and treated with hydrazoic acid to give 5-alkyl-3-acetyltropolones 7a-d.
通过烷基环戊二烯2a-d与丙酮的碱性缩合制备的2-烷基取代的6,6-二甲基富烯3a-d与二氯乙烯酮反应得到2-烷基取代的7,7-二氯-4-异亚丙基双环[3.2。 0]庚-2-en-6-酮4a-d。 将环加合物4a-d在乙酸钠存在下在乙酸水溶液中水解,得到5-烷基取代的3-异丙烯基托酚酮(2-羟基-3-异丙烯基-2,4,6-环庚三烯酮)5a-d。这些3-异丙烯基托酚酮5a-d在5%钯-炭上氢化,得到5-烷基-3-异丙基托酚酮6a-d,并用叠氮酸处理,得到5-烷基-3-乙酰基托酚酮7a-d。