Intramolecular photocycloaddition of olefin-tethered benzo[a]spiro[2,5]octa-1,4-dien-3-one derivatives
作者:Xuqing Zhang、Arthur G. Schultz
DOI:10.1016/s0040-4039(02)00518-x
日期:2002.4
derivative 8a afforded spiro-fused tetracycles 10 as a pair of diastereomers in 1.7:1 ratio. The photochemical process occurred by cycloaddition of the intermediate-sulfone stabilized biradical 9 to the tethered olefin. Photolysis of dienone 8b gave only spiro-fused tetracycle 11 without bridged adduct 12.
苯并[ a ]螺[2,5]八-1,4-二烯-3-酮衍生物8a的光解提供了螺环稠合的四环化合物10,其为一对非对映体,比例为1.7:1。光化学过程是通过将中间体砜稳定的双基9环加成到束缚的烯烃上而发生的。二烯酮8b的光解仅产生螺旋稠合的四环11,而没有桥接的加合物12。