Heterocyclic rearrangements. Part XIV. Attempts to activate ring-opening–ring-closure rearrangements with carbon as the central atom

Various 3-substituted quaternised pyridines and 4-substituted oxazoles have been prepared and studied, with a view to discovering substituents appropriate for reactions involving opening of the pyridine or oxazole ring with closure onto the substituent to form a new ring at the 2-(pyridine) or 5-(oxazole) position. None of these potential rearrangements succeeded; the reasons for this are discussed together with the evidence that this provides for the mechanism of previously reported rearrangements.