Syntheses and Properties of α-Ethyl-substituted Bisdehydroannulenone and Its Benzo-annelated Derivatives

Article abstract of DOI:10.1246/bcsj.54.3466

2-Ethyl-5,10-dimethyl-, 13-ethyl-10-methyl-4,5-benzo-, 2-ethyl-10-methyl-4,5-benzo-, and 2-ethyl-4,5:10,11-dibenzo-6,8-bisdehydro<13>annulenone were synthesized.Influence of α-ethyl substitution upon the skeleton of the bisdehydro<13>annulenone ring system is discussed on the basis of 1H NMR and UV spectra of these annulenones and their corresponding α-methyl-substituted derivatives.