Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work describes the synthesis and characterization of 2-trihaloacetylmetoxycycloalkenes series derived from cyclical ketones (cyclohexanone, cycloheptanone, cyclooctanone and cyclododecanone). The 2-trihaloacetyl-1-metoxycycloalkenes were obtained from the reaction of trihaloacetylation of 1.1-dimetoxycycloalkanes. Eight 2-trihaloacetyl-1-metoxycycloalkenes have been synthesized, and four of these trichloroacetyl compounds are unprecedented in the literature. The 2-trifluoroacetyl-1-metoxycycloalkenes were employed in the regiospecific synthesis of 3-hydroxy-3-trifluoromethyl-cycloalka[c]isoxazole, 3-trifluoromethyl-cycloalka[c]isoxazole, 3-trifluoromethyl-cycloalka[c]1H-pyrazole, 2-acetyl-3-hydroxy-3-trifluoromethyl-cycloalka[c]1H-pyrazole, 2-carboxyamide-3-hydroxy-3-trifluoromethyl-cycloalka[c]1H-pyrazole, 4-(3-hydroxy-3-trifluoromethyl-cycloalka[c] pyrazole-2-yl]-7-chloroquinoline. The reactions of cyclocondensation employed 2-trifluoroacetyl-1- metoxycycloalkenes and five different 1,2-dinucleofiles (hydroxylamine, hydrazine hydrochloride, acetic hydrazine, semicarbazide and 4-hydrazine-7-chloroquinoline), leading to yield between 34-85%. All compounds were characterized by spectral and analytical experiments, 1H's and 13C's NMR, and its purity was demostrated by CG/MS and elemental analyses. / Este trabalho descreve a síntese e caracterização de uma série de 2-trialoacetil-1-metoxicicloalquenos derivados de cetonas cíclicas (ciclopentanona, cicloexanona, cicloeptanona, ciclooctanona e ciclododecanona). Os 2-trialoacetil-1-metoxicicloalquenos foram sintetizados a partir da reação de trialoacetilação de 1,1-dimetoxicicloalcanos. Foram sintetizadas oito 2-trialoacetil-1-metoxicicloalquenos, sendo que quatro destes compostos tricloroacetilados são inéditos na literatura. Os 2-trifluoracetil-1-metoxicicloalquenos foram empregados na síntese regioespecífica de 3-hidróxi-3-trifluormetil-cicloalca[c]isoxazol, 3-trifluormetilcicloalca[ c]isoxazol, 3-trifluormetil-cicloalca[c]1H-pirazol, 2-acetil-3-hidróxi-3-trifluormetil-cicloalca[c]1H-pirazol, 2-carboxiamida-3-hidróxi-3-trifluormetilcicloalca[c]1H-pirazol, 4-{3-hidróxi-3-trifluormetil-cicloalca[c]pirazol-2-il]-7-cloroquinolina. As reações de ciclocondensação empregaram 2-trifluoracetil-1- metoxicicloalquenos e cinco diferentes 1,2-dinucleófilos, hidroxilamina, cloridrato de hidrazina, hidrazina acética, semicarbazida e 4-hidrazina-7-cloroquinolina, levando a rendimentos entre 34-85%. A análise estrutural de 2-trialoacetil-1-metoxicicloalquenos, bem como os cicloalca[c]azo compostos sintetizados foram caracterizados por experimentos de RMN de 1H, 13C, e sua pureza determinada via CGMS e análise elementar.