Electrophilic Intramolecular Cyclization of 1-(N-alkenyl)-6-methylpyrimidine-2,4-diones
N-allyl(cinnamyl)substituted derivatives of 6-methyluracil were synthesized. The reactions of their bromo- and iodocyclization were performed which led to the formation of the derivatives of dihydro¬oxazolo¬pyrimidinium and dihydrooxazinepyrimidinium. The factors that favor the regioselectivity of these reactions were suggested.