Base-Promoted Rearrangement of 1,5-Dibromopentacyclo[5.3.0.0<sup>2,5</sup>.0<sup>3,9</sup>.0<sup>4,8</sup>]decane-6,10-dione: Easy Entry of a Novel Cage System, 10-Oxa-9-oxopentacyclo[5.3.0.0<sup>2,4</sup>.0<sup>3,6</sup>.0<sup>5,8</sup>]decane
作者:Tomohiro Nigo、Takeshi Hasegawa、Yoshiyuki Kuwatani、Ikuo Ueda
DOI:10.1246/bcsj.66.2068
日期:1993.7
product 7. Deacetalization was accomplished by treating with concentrated sulfuric acid to give 1,5-dibromopentacyclo[5.3.0.02,5.03,9.04,8]decane-6,10-dione (9). Compound 9 was converted into a new cage system, 10-oxa-9-oxopentacyclo[5.3.0.02,4.03,6.05,8]decane, in a high yield by treating with 5% aqueous potassium hydroxide at 80 °C.
2-溴-2,4-环戊二烯酮乙缩醛 (2) 的狄尔斯-阿尔德二聚反应得到内-2,7-二溴二环戊二烯-1,8-二酮 1,8-双 (乙缩醛) (3) 作为次要产物产率为 4.5%。紫外线照射 5 产生二聚产物 7。通过用浓硫酸处理来完成脱缩醛反应,得到 1,5-二溴五环 [5.3.0.02,5.03,9.04,8]癸烷-6,10-二酮 (9)。通过在 80 °C 下用 5% 氢氧化钾水溶液处理,将化合物 9 转化为新的笼系统,即 10-oxa-9-oxopentacyclo[5.3.0.02,4.03,6.05,8]decane。