Synthesis of the first 3,6,9,15,18,18-hexa-substituted-1,2,4,5,7,8,10,11,13,14,16,17-dodecadehydro[18]annulenes with D6h-symmetry
作者:Yoshiyuki Kuwatani、Naoto Watanabe、Ikuo Ueda
DOI:10.1016/0040-4039(94)02181-a
日期:1995.1
3,6,9,12,15,18-Hexaphenyl-1,2,4,5,7,8,10,11,13,14,16,17-dodecadehydro[18]annulene and related compounds have been synthesized. These compounds were found to be stable both in crystalline forms and chloroform solution at room temperature, to have aromatic character by the existance of a diamagnetic ring current on the basis of the nmr spectral data, and to conform to the D6h-symmetry group.
3,9,15-Tris(p-tert-butylphenyl)dodecadehydro[18]annulene (6) and 3,6,9,12,15,18-hexa-substituted dodecadehydro[18]annulenes (7, 8, and 9) have been prepared. These compounds were shown to be heated up to 150 °C without decomposition. The molecular structure of 7 was determined by X-ray crystallography, which showed that 7 has a planar π-system with D6h-symmetry. The UV and NMR spectral data indicate