Cycloadditions of substituted benzopyran-4-ones to electron-rich dienes: a new route to xanthone derivatives
作者:Peter J. Cremins、Suthiweth T. Saengchantara、Timothy W. Wallace
DOI:10.1016/s0040-4020(01)86849-6
日期:1987.1
3-butadiene 12 to give the respective adducts 13,14, and 18 as mixtures of C-l stereoisomers. Heating the 3-arylsulphinylchromone 5 with the diene 12 afforded 3-hydroxyxanthone 23 in 50% yield, the presumed cycloaddition - elimination sequence constituting a new route to xanthone systems. Desilylation of 13,14, and 18 in acidic media provided 25,26, and 27 respectively.
在氯化钛(IV)的存在下,苯并吡喃酮1和3与2,3-二甲基-1,3-丁二烯反应,得到相应的(4 + 2)环加合物8和11,前者进行了简单的甲酰基化,得到9和10。化合物1,3和4例行高效非催化环加成到1-甲氧基-3-(三甲基甲硅烷基)-1,3-丁二烯12,得到相应加合物13,14,和18例如Cl立体异构体的混合物。用二烯12加热3-芳基亚磺酰基色酮5以50%的收率得到3-羟基黄酮23,假定的环加成-消除顺序构成了通往黄酮系统的新途径。在酸性介质中进行13,14和18的脱甲硅烷基分别提供25,26和27。