Unexpected pathway of the reaction of N-[(β-halogeno-α-tosyl)alkyl]ureas with β-oxoester enolates. Synthesis of ethyl 5-ureido-4,5-dihydrofuran-3-carboxylates and N-carbamoylpyrrole-3-carboxylates
Keywords: پیرول; β-Halogeno-α-tosyl-substituted N-alkylureas; Nucleophilic substitution; α-Halogeno N-acylimines; Dihydrofurans; Pyrroles;