TRANSFORMATIONS OF N-ACETYL(AROYL)-1-AZAFLUORENIUM CHLORIDES TO GIVE 9-α-HYDROXYETHYLIDENE(ARYLIDENE)-1-AZAFLUORENES
N-Acetyl(benzoyl)-1-azafluorenium chlorides were converted to 9-acetyl(benzoyl)-1-azafluorenes, which exist in the enol form, when they were treated with triethylamine in benzene in the presence of boron trifluoride etherate.The first step in the rearrang