Formation of Benzoic Acid and Acetophenone from Dypnone in the Presence of BF3-Water Complexes

Abstract

Dypnone [3] undergoes BFs-catalyzed bond cleavages to form benzoic acid [1] and 2, 4, 6- triphenylpyrylium fluoborate [4] (A cleavage reaction) and acetophenone [2] (B cleavage reaction). As the other reaction product, 1, 1, 3-trimethyl-3-phenyl-hydrindene [7] which is a dimer ofα-methylstyrene [6] is obtained. Thus A cleavage reaction is verified.
Difference in activities of two BF3-water complexes (BF3H₂0 and BF32H₂10) for the two cleavage reactions (A and B) is examined. For A cleavage reaction, BF3-1-120 is remarkably active, but BF3.2 H₂O is not so. B cleavage reaction is much easier to be catalyzed than A cleavage reaction and is activated even by BF3, H₂0.