Concerning the reported formation of 3,4,4-Triphenylisoxazoline from 1-aci-Nitro-1,2,2-triphenylpropane under acidic conditions. Acid catalysed fragmentation of secondary aci-Nitro compounds

Abstract

Treatment of 1-aci-nitro-1,2,2-triphenylpropane (1) with hydrochloric acid leads to the formation of 3,5,5-triphenylisoxazoline (3), not 3,4,4-triphenylisoxazoline (2) as previously reported. The route from (1) to (3) has been shown to involve a fragmentation of the aci-nitro compound, similar to the ?abnormal? Beckmann rearrangement of oximes, to give 1,1-diphenylethylene and benzonitrile oxide, which then combine in a 1,3-dipolar addition.