RING-REARRANGEMENT DURING THE MITSUNOBU A LKYLATION OF PHTHALAZINONESAND INDAZOLOLS

The Mitsunobu alkylation of substituted phthalazinones and indazolols with cyclic hydroxy- and hydroxymethyl-substituted amines was investig ated. In addition to the expected derivatives ring-narrowed and ring-e nlarged rearrangement products were isolated and characterized by NMR spectroscopy. The occurrence of these products can be explained by the existence of a bicyclic intermediate. The results of the reaction of phthalazinones with optically active amine compounds show a stereospec ific reaction mechanism. The reaction of the phthalazinones leads to N -substituted derivatives were isolated. A postulated bicyclic intermed iate, 1-methyl-1-azoniabicyclo[3.2.0]heptane, was synthesized as chlor ide.