Intramolecular Dehydro Diels−Alder Reactions of Diarylacetylenes: Switching between Benzo[<i>b</i>]- and Benzo[<i>c</i>]fluorenones as Products by Controlling the Rearrangement of Cyclic Allene Intermediates
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。
A New Modification of the Ullmann Synthesis of Fluorene Derivatives
作者:Warren C. Lothrop、Paul A. Goodwin
DOI:10.1021/ja01243a019
日期:1943.3
Contribution à l'étude des dibenzofluorènes: le dibenzo-2, 3, 5, 6-fluorène
作者:R. H. Martin
DOI:10.1002/hlca.19470300225
日期:1947.3.15
1. La dibenzo-2,3,5,6-fluorénone a été synthétisée par condensation du dialdéhyde phtalique avec la benzo-4,5-hydrindone. La structure de la cétone a été confirmée par dégradation.