%0 Journal Article %A Teixeira, Wystan K. O. %A Gonçalves, Helena A. %A de Mello, Débora L. %A Moura, Sidnei %A C. Flores, Darlene %A F. C. Flores, Alex %D 2017 %T Cyclocondensation between fatty acid hydrazides and 1,1,1-trifluoro-4-alkoxy-3-alken-2-ones: Introducing a trifluoromethylated head onto fatty acid moieties %U https://tandf.figshare.com/articles/journal_contribution/Cyclocondensation_between_fatty_acid_hydrazides_and_1_1_1-trifluoro-4-alkoxy-3-alken-2-ones_Introducing_a_trifluoromethylated_head_onto_fatty_acid_moieties/5303308 %R 10.6084/m9.figshare.5303308 %2 https://tandf.figshare.com/ndownloader/files/9082900 %K 1,1,1-Trifluoro-4-alkoxy-3-alken-2-ones %K 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazoles %K [3 + 2] cyclocondensation %K fatty hydrazides %X

This paper reports the regioselective synthesis of new trifluoromethylated lipid derivatives, namely, 1-(5-hydroxy-5-trifluoromethyl-3-alkyl-4,5-dihydro-1H-pyrazol-1-yl)alkan-1-ones, through cyclocondensation reactions between a series of fatty hydrazides (palmitoyl, stearoyl, and oleoyl hydrazides) obtained from fatty acids from renewable resources (1,1,1-trifluoro-4-alkoxy-3-alken-2-ones [F3CC(O)CH˭C(R1)OR, where R1 = H and R˭Et; R1 = –(CH2)6CH3, –(CH2)6CH3, –(CH2)8CH3, –(CH2)9CH3, –(CH2)10CH3, –(CH2)12CH3, –(CH2)2Ph], and R˭Me). Experimental observations showed that the lipophilic characteristic of 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazoles (5–7) prevent the acid catalyzed dehydration to aromatization of 1H-pyrazole ring, although in some cyclocondensations a proportion of the aromatic derivative 1-(5-trifluoromethyl-3-alkyl-1H-pyrazol-1-yl)alkan-1-one was obtained. All products were characterized using multinuclear (1H, 13C, 19F) NMR spectroscopy.

%I Taylor & Francis