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。