[2 + 2] Cycloaddition reaction of cycloheptatriene with dichloroketene. A novel and efficient synthetic strategy for the synthesis of 2-hydroxyazulene
作者:Ryuji Yokoyama、Shunji Ito、Masataka Watanabe、Nobuyuki Harada、Chizuko Kabuto、Noboru Morita
DOI:10.1039/b104164a
日期:——
0]nona-3,5-diene-8,2′-oxetan)-4′-one 7 without any decarbonylation. The reaction of 2 with diazomethane exhibits ring expansion of the four-membered ring to give 1,1-dichloro-3,3a,4,8a-tetrahydroazulen-2(1H)-one 8. 2-Hydroxyazulene 9 is successfully derived by the reaction of 8 with lithium chloride in good yield. The reaction of 8 with triethylamine exhibits dehydrochlorination to give 3-chloro-8
的反应 环庚三烯 和 二氯乙烯酮,由治疗产生 三氯乙酰氯 干燥的锌 乙醚,提供9,9-dichlorobicyclo [5.2.0] nona-2,4-dien-8-one 2作为主要产品3′,3′,9,9-四氯螺(双环[5.2.0] nona-2,4-diene-8,2′-oxetan)-4′-one 3。通过对其部分还原的产物的X射线晶体学分析阐明了结构3。内酯 3在七元环中显示[1,5]氢迁移,得到3',3',9,9-四氯螺(bicyclo [5.2.0] nona-3,5-diene-8,2'-oxetan )-4′-一7没有任何脱羰作用。的反应2与重氮甲烷 展品 扩环 四元环的 1,1-二氯-3,3a,4,8a-四氢azulen-2(1 H)-one 8。2-羟基az 9是通过8与氯化锂产量高。反应8与三乙胺 表现出脱氯化氢作用 3-氯-8,8a-二氢azulen-2(1 H)-one