Syntheses and Reactions of Spiroanthronetriazolines

Article abstract of DOI:10.1021/jo01297a028

Quinone methide 1a reacts with aryl azides 2 to give the corresponding spiroanthronetriazolines 3 along with byproducts, collected in Table I, which are formed by the thermal reaction of 3 or 1a.Quinone methide 1b adds to azides 2 to give spiroanthronetriazolines 5 or their subsequent products.Pyrolysis of 3 regenerates the starting quinone methide 1a and azide 2, and their photolysis leads to 1a.Pyrolysis and photolysis of 5 yield aryliminoanthrone 7, arylaminodibenzocycloheptenone 12, or its isomer 19.Attempts to convert 3 and 5 into spiroanthroneaziridines 14 and 15, respectively, were unsuccessful.Reactions of 3 and 5 with acid catalysts give the rearrangement products dibenzocycloheptenediones 23 and 24, respectively, in high yields.These reactions are discussed in mechanistic terms.