CYCLIZATION WITH NITRENIUM IONS GENERATED FROM N-METHOXY- OR N-ALLYLOXY-N-CHLOROAMIDES WITH ANHYDROUS ZINC ACETATE - SYNTHESIS OF N-HYDROXY- AND N-METHOXYNITROGEN HETEROCYCLIC-COMPOUNDS

Electrophilic intramolecular aromatic substitution with an N-methoxy- or an N-allyloxy-acylnitrenium ion, generated by treatment of an N-met hoxy- or an N-allyloxy-N-chloroamide with anhydrous zinc acetate in ni tromethane, leads to formation of a nitrogen heterocyclic compound bea ring an N-methoxy- or N-allyloxy group. The latter is readily converte d to the corresponding N-hydroxy compound by palladium-catalyzed remov al of the allyl group.