Thermal cyclization of 1-[2-(arylethynyl)phenyl]-3-trimethylsilylpropynones affords a mixture of benzo[b]fluorenones and benzo[c]fluorenones. The ratio of the two isomers can be efficiently varied between 100:0 and 0:100 by introducing substituents with appropriate electronic and steric properties on the aryl rings and using an appropriate solvent.
1- [2-(芳
乙炔基)苯基] -3-三甲基甲
硅烷基
丙炔酮的热环化得到苯并[ b ]
芴酮和苯并[ c ]
芴酮的混合物。通过在芳基环上引入具有适当电子和空间性质的取代基并使用适当的溶剂,可以有效地在100:0和0:100之间改变两种异构体的比例。