Аннотация:The action of base on trisubstituted N-alkyl isoxazolium salts, first described by Kohler and co-workers (1, 2), has been reinvestigated. On the basis of photochemical and spectroscopic studies it is concluded that the reaction of the N-methyl triphenylisoxazolium ion (Ia) with aqueous sodium hydroxide leads to 4,5,6-triphenyl-2H-1,3-oxazine (III), a derivative of a heterocycle previously known only in benz-fused systems.
