A series of functionalized 1,1,1-trihalo-4-methoxy-3-alken-2-ones [CX3C(O)CR1=CROMe, where X = F or Cl; R = n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-tridecyl, (CH2)2CH=C(Me)2, (CH2)2Ph, (CH2)2-(4-HOC6H4), (CH2)2-(4-MeOC6H4), (CH2)2CO2Me, (CH2)3CO2Me, CH(SMe)CH3, CH2(2-MeOC6H4), and R1 = H, and R = H and R1 = n-decyl] were synthesized from respective alkyl methyl ketones or aldehyde via acetal acylation using trifluoroacetic anhydride and trichloroacetyl chloride. 1,1,1-Trihalo-4-methoxy-3-alken-2-ones with acid-compatible substituents were easily hydrolyzed to respective trihalomethyl-1,3-diketones. The 1,1,1-trihalo-4-methoxy-3-alken-2-ones and/or respective trihalomethyl-1,3-diketones were reacted regiospecifically with hydroxylamine hydrochloride, leading to isoxazole derivatives, and with hydrazines, leading to respective 1H-pyrazole derivatives. The structures of all compounds were assigned based on nuclear magnetic resonance (NMR) and mass spectrometric data. This method represents an efficient pathway for the regioselective trihaloacetylation of asymmetrically substituted alkyl methyl ketones and highly self-condensing aldehydes. Moreover, this approach allows the introduction of biologically recognizable moieties, such as those from levulinic acid, sulcatone (prenyl), benzylacetone, anisylacetone, and raspberry ketone, as synthetic molecular targets.

A síntese eficiente de novas 1,1,1-tricloro-4-metoxi-3-alquen-2-onas graxas [Cl3CC(O)C(R²)=C(R¹)OMe, onde R¹ = n-hexil, heptil, nonil, undecil, tridecil e R² = H] e 1,1,1-tricloro-2,4-alkanediones [Cl3CC(O)CHR²C (O) R¹, onde R¹ = n-pentil e R² = Me, R¹ = Et e R² = n-butil, R¹ = n-butil e R² = n-propil] é apresentada, com bons rendimentos (85-95%) a partir da acilação dos respectivos acetais com cloreto de tricloroacetila. As 1,1,1-tricloro-4-metoxi-3-alquen-2-onas e 1,1,1-tricloro-2,4-alkanediones graxas reagem com cloridrato de hidrazina produzindo os respectivos 1H-pirazol-5-carboxilatos, uma classe de novos ésteres metílicos (FAMEs) e etílicos (FAEEs) graxos não comuns. As estruturas moleculares dos compostos sintetizados foram confirmadas por análise elementar e ressonância magnética nuclear (NMR) de ¹H e 13C. As 1,1,1-tricloro-4-metoxi-3-alquen-2-onas graxas e seus derivados 1H-pirazol-5-carboxilatos são novos oleoquímicos com propriedades diferenciadas e potencialmente interessantes.

The efficient synthesis of new fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones [Cl3CC(O)C(R²)=C(R¹)OMe, where R¹ = n-hexyl, heptyl, nonyl, undecyl, tridecyl and R² = H] and 1,1,1-trichloro-2,4-alkanediones [Cl3CC(O)CHR²C(O)R¹, where R¹ = n-pentyl and R² = Me, R¹ = Et and R² = n-butyl, R¹ = n-butyl and R² = n-propyl] in good yields (85-95%) from acetal acylation with trichloroacetyl chloride is reported. The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1,1,1-trichloro-2,4-alkanediones were reacted with hydrazine hydrochloride, leading to respective 1H-pyrazole-5-carboxylates, unusual class of fatty acid methyl (FAMEs) and ethyl (FAEEs) esters. Their structures were confirmed by elemental analysis and ¹H and 13C nuclear magnetic resonance (NMR). The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1H-pyrazole derivatives are new oleochemicals with potentially interesting and differential properties.