Synthesis of the ω-brominated α-trifluoroacetylcycloalkanones and their isoxazole derivatives

Abstract

The reactions of a serie of the 2-trifluoroacetyl-1-methoxy-1-cycloalkenes (1a-1e) and 2-trifluoroacetylcycloalkanones (2a-2e) with molecular bromine to obtain ω-bromo-α-trifluoroacetylcycloalkanones (3a-3e, 4a) is reported. Was determined that 2-trifluoroacetyl group have established the C-omega as reactive site. The 2-trifluoroacetylcycloalkanones and ω-bromo-α-trifluoroacetylcycloalkanones were reacted with hydroxylamine hydrochloride leading to respective 5-trifluoromethyl-5-hydroxy-4, 5-dihydro-3,4-polimethyleneisoxazole derivatives (5c-Se and 6c-6e). © 2006 Sociedade Brasileira de Química.