Novel and efficient one-pot synthesis of azuleno[1,2-<i>b</i>]-benzothiophenic enones from the corresponding 2-cycloheptatrientyl-3-(2-furyl)benzothiophenes
2-Cycloheptatrienyl-3-(2-furyl)benzothiophenes, which are prepared by Stille coupling reaction of 2-cyclo-heptatrienyl-3-bromobenzothiophene with the 5-substituted 2-trimethylstannylfurans, react with triphenylmethyl tetrafluoroborate to give the correspondingazuleno[1,2-b]benzothiophenic enones in excellent yields.