Synthesis of 2,2-dimethylchromans by the hydrogenation of 2,2-dimethyl-2H-chromenes
摘要:
2,2-Dimethylchromans 19-36 have been synthesized by the hydrogenation of 2,2-dimethyl-2 H-chromenes 1-18 in acetic acid solution in the presence of 10% Pd-C catalyst.
Structural features controlling cation-radical line-broadening in the 1H-NMR spectra of phenol derivatives in acid media
作者:Isam K.L. Al-Khayat、Francis M. Dean、Rajender S. Varma
DOI:10.1016/s0040-4020(01)86907-6
日期:1987.1
of cationradicalsfrom 2,3,4,7-8,9-hexahydro-2,2,5.7,7, 10-hexamethylbenzo[1,2-b; 4,5-b']dipyran (1) and the isomeric benzo[1,2-b; 4,3-b']dipyran (3) have been characterised. The production of cationradicalfrom (1) in acid media is limited by acid concentration for weak acids and also by the presence of oxygen for strong acids. The cationradical species (Ar+) is considered to originate from substrate