Acetals
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. SYNTHESIS AND ANTIFUNGAL ACTIVITY OF PALMITIC ACID-BASED NEOGLYCOLIPIDS RELATED TO PAPULACANDIN D
A series of six new palmitic acid-based neoglycolipids related to Papulacandin D were synthesized in five steps, resulting in good yields, and they were evaluated against Candida spp. All twelve synthetic intermediates were also evaluated. The synthesis involved the initial glycosylation of two phenols (4-hydroxy-3-methoxybenzaldehyde and 3-hydroxybenzaldehy
Quím. Nova. Publicado em: 2015-12
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2. REAÇÃO DE CONDENSAÇÃO DO GLICEROL COM COMPOSTOS CARBONÍLICOS. SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO EM CRISTAIS LÍQUIDOS
Condensation reactions of glycerol with aldehydes and ketones were performed under thermal heating and microwave irradiation regimes. Homogeneous and heterogeneous catalysts were tested in both conditions. A silica sulfated (SiO2-SO3H) heterogeneous catalyst demonstrated the best performance relative to a selectivity of >95% in favor of 5-membered ketals. Fo
Quím. Nova. Publicado em: 2015-09
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3. Reactivity of glycerol/acetone ketal (solketal) and glycerol/formaldehyde acetals toward acid-catalyzed hydrolysis
Foi investigado o efeito da temperatura, razão molar e quantidade de catalisador na hidrólise ácida do cetal de glicerol/acetona (solketal) e acetais de glicerol/formaldeído. A reatividade do solketal foi bem maior que a dos acetais de glicerol/formaldeído. A 80 ºC, 5:1 de razão molar água/cetal e uma quantidade de catalisador correspondendo a 3.0 mm
Journal of the Brazilian Chemical Society. Publicado em: 2012-05
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4. Aplicação de α-oxoceteno ditiocetais em síntese orgânica
The synthesis and reactivity of α-oxoketenes dithioacetals (S,S-acetals), general structure [(R¹C=OC(R²)=C(SR³)(SR4)], are reported. We also showed the application of S,S acetals as synthons for efficient synthesis of isoxazoles, pyrazoles, indazoles, thiophenes, dithiol thiones, pyridines, pyrimidines and other heterocycles. This work aims to review the
Química Nova. Publicado em: 2010
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5. SÍNTESE DE 1,7-FENANTROLINAS E 7-AMINOQUINOLINAS TRIFLUORMETIL SUBSTITUÍDAS / SYNTHESIS OF TRIFLUOROMETHYL SUBSTITUTED 1,7-PHENANTHROLINES AND 7-AMINOQUINOLINES
This work, at first, describes the synthesis and characterization of new series of (Z,Z)-N,N-bis(oxotrifluoroalkenyl)-1,3-phenylenediamines by the addition/elimination reaction of β-alkoxyvinyl trifluoromethyl ketones with 1,3-phenylenediamine, in 47-91 % yields. The 4-alkyl[aryl(heteroaryl)]-4-alkoxy-1,1,1-trifluoro-3-alken-2-ones, of general formula F
Publicado em: 2010
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6. 1-(2,4-dichlorophenyl-1H-pyrazoles: Synthesis, Structural Analysis and Interactions with Cannabinoid Receptors CB1 / 1-(2,4-Diclorofenil)-1H-pirazóis: Síntese, Análise Estrutural e Interação com os Receptores Canabinóides CB1
A method to obtain fourteen enones [EtO2CC(O)C(R2)=C(R1)OR, where R = H, Me; R1 = Pr, Ph, 4-MeOC6H4, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-NO2C6H4, Fur- 2-yl; R2 = H; R1,R2 = -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, 3,4-dihydronaphthalen-2-yl] from acylation of acetals with ethyl oxalyl chloride is reported. The cyclocondensation reaction of these substrat
Publicado em: 2010
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7. USING OF THE IONIC LIQUIDS IN THE SYNTHESIS OF ENONES AND ENAMINONES / UTILIZAÇÃO DE LÍQUIDOS IÔNICOS NA SÍNTESE DE ENONAS E DE ENAMINONAS
The use of ionic liquids 1-butyl-3-methylimidazolium tetrafluorborate ([BMIM] [BF4]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) as catalytic solvent in the synthesis of 1,1,1-trichloro(fluoro)-3-alken-2-onas [CX3C(O)C(R2)=C(R1)OR] from the reaction of enolethers or acetals with acyl halides is reported. The results obtained in the pres
Publicado em: 2009
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8. Gliceroquímica: novos produtos e processos a partir da glicerina de produção de biodiesel
Glycerol is a byproduct of biodiesel production through transesterification of oils and fat. This article discusses the chemical transformation of glycerol in ethers, acetals and esters of high technological applications, especially in the fuel sector. Glycerol hydrogenolysis, dehydration to acrolein and oxidation are discussed as well, to show the potential
Quím. Nova. Publicado em: 2009
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9. Preparation of novel trifluoroacetylketene O,N-acetals and trifluoromethyl-containing S,S-sulfoximido N-substituted heterocycles
Este trabalho descreve a síntese de dois novos trifluoracetilceteno O,N-acetais [CF3C(O) CH=C(OEt)(NS(O)R2), onde R = CH3, Ph], obtidos da reação de 4,4-dietóxi-1,1,1-trifluorbut-3- en-2-ona [CF3C(O)CH=C(OEt)2] com S,S-dimetil- e S-metil-S-fenil-sulfoximida [HN=S(O)R2], na presença de trietilamina, com rendimentos de 60-72%, e suas aplicações na obten
Journal of the Brazilian Chemical Society. Publicado em: 2009
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10. SYNTHESIS OF 1,2,4-TRIAZOL-5-YLAMINO PYRIMIDINES TRIFLUOROMETHYL SUBSTITUTED / SÍNTESE DE 1,2,4-TRIAZOL-5-ILAMINO PIRIMIDINAS TRIFLUORMETIL SUBSTITUÍDAS
This work describes the synthesis and characterization of fourteen 4-trifluoromethyl-2-[3-(pyridyl)-1H-1,2,4-triazol-5-ylamino]pyrimidines (6, 7), from the cyclocondensation reaction of N-[3-(pyridyl)-1H-1,2,4-triazol-5-yl]guanidines (4, 5), a 1,3-dinucleophile precursor of the type (N-C-N), with 1,1,1-trifluoro-4-alkoxy-3-alken-2-ones (1), a versatile 1,3-d
Publicado em: 2009
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11. OBTENÇÃO QUIMIOSSELETIVA DE TRIALOMETIL-β-DICETONAS VIA REAÇÕES DE ACILAÇÃO DE ACETAIS / QUIMIOSELETIVE OBTENTION OF TRIALOMETHYL-β-DIKETONES FROM ACYLATION REACTIONS OF ACETALS
Este trabalho apresenta um método de acilação de acetais aplicado à obtenção quimioseletiva de trialometil-β-dicetonas, inclusive a partir de acetais derivados de cetonas não simétricas, e com os substituintes funcionalizados. Foram obtidas cinco 1,1,1-trialo-4-metóxi-3-alquen-2-onas inéditas [X3CCOCH=C(OMe)R] as quais foram hidrolisadas até
Publicado em: 2009
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12. USE OF MICROWAVE IRRADIATION IN THE SYNTHESIS OF ENONES AND 4,5-DIHYDRO-1H-PYRAZOLES TRIHALOMETHYL-SUBSTITUTED / USO DE ENERGIA MICROONDAS NA SÍNTESE DE ENONAS E DE 4,5-DIIDROPIRAZÓIS TRIALOMETIL-SUBSTITUÍDOS
The solvent-free microwave-assisted regiospecific synthesis of a series of 5-trihalomethyl-4,5-dihydro-1H-pyrazole (7 - 10) from the cyclocondensation of 1,1,1- trihalo-4-alkoxy-3-alken-2-ones (5 - 6),[ CX3COC(R)2=C(R)1OR, where X = Cl, F; R = Me, Et; R2 = H, Me and R1 = H, Me, Et, Pr, iso-Pr, Bu, iso-Bu, tert-Bu, iso - Pen, Ph, 4-Me-Ph, 4-MeO-Ph, 4-NO2-Ph,
Publicado em: 2008