Abstract:
O presente trabalho apresenta a aplicação do método de Acilação de Acetais, na obtenção regiosseletiva de precursores 1,3-dieletrofílicos, β-alcoxivinil trialometil cetonas, a partir da reação do dimetoxicetal derivados das cetonas: 4-fenilbutan-2-ona (benzilacetona) (a), 4- (4-metoxifenil)-butan-2-ona (anisilacetona) (b), 4- (4-hidroxifenil)butan-2-ona (raspberry ketone) (c), 4- (4-hidroxi-3-metoxifenil)butan-2-ona (gingerona ou vanilil cetona) (d), 4-(2,6,6-trimetilciclohex-1-en-1-il)butan-2-ona (diidro-β-ionona) (e), e do dietoxiacetal derivado do aldeído Laúrico (f), utilizando-se agente acilante fluorado. Foram obtidas β-dicetonas inéditas, a partir da hidrólise das alquil metil cetonas (a-e) sintetizadas. As β-dicetonas a,b,e mostraram-se importantes ligantes, para reação de complexação, com acetatos de cobre (II) e níquel (II), obtendo-se diferentes complexos. São apresentadas rotas sintéticas eficientes e regio específicas a partir da reação de ciclocondensação [3+2] entre os precursores 1,3-dieletrofílicos 2a,b, com cloridrato de hidrazina, até a formação de pirazóis funcionalizados com cadeia lateral diversificadas.Todos os produtos foram caracterizados por Ressonância Magnética Nuclear (RMN) de 1H e 13C.
The present work presents the application of the Acetyl Acylation method in the regioselective preparation of 1,3-dielectrophilic precursors, β-alkoxyvinylthiodomethylethyl ketones, from the reaction of dimethoxyketal derived from ketones: 4-phenylbutan-2-one (benzylacetone) (a), 4- (4-methoxyphenyl) -butan-2-one (anisylacetone) (b), 4- (4-hydroxyphenyl) butan-2-one (raspberry ketone) (c), 4- (4-hydroxy- -3-methoxyphenyl) butan-2-one (gingerone or vanillyl ketone) (d), 4- (2,6,6-trimethylcyclohex-1-en-1-yl) butan-2-one (dihydro-β-ionone ) (e), and diethoxyacetal derived from Lauric aldehyde (f), using fluorinated acylating agent. Unpublished β-diketones were obtained from the hydrolysis of the synthesized alkyl methyl ketones (a-e). The β-diketones a,b,e and showed important binders, for complexation reaction, with copper (II) and nickel (II) acetates, obtaining different complexes. Efficient and regiospecific synthetic routes are presented from the cyclocondensation reaction [3 + 2] between the 1,3-dielectrophilic precursors 2a,b, with hydrazine hydrochloride, until the formation of reversed side-chain functionalized pyrazoles. All the products were characterized by 1H and 13C Nuclear Magnetic Resonance (NMR).
