A closer examination of the mechanism for photolytic ring-opening of cyclohexa-2,4-dienones
作者:Peter M. Collins、Harold Hart
DOI:10.1039/j39670001197
日期:——
Irradiation of cyclohexa-2,4-dienones in methanol through Pyrex affords cis-ketens, which then react with methanol by 1,2-addition to give βγ:δε-unsaturated esters. This is true even of dienones with alkyl groups in the 2-, 4-, and 6-positions. The cis-geometry is maintained at the βγ double bond of the ester, although cis-ester can isomerise to trans-ester on irradiation through Vycor. In one case