RESUMO
Porcine pancreatic lipase in tetrahydrofuran catalyses the deacetylation of 2,4-diacetoxyphenyl alkyl ketones in a highly regioselective fashion. The strategy of regioselective deacetylation of diacetoxyphenyl alkyl ketones has also resulted in the enantiomeric resolution of a racemic diacetoxyphenyl alkyl ketone, i.e. (+/-)-2,4-diacetoxyphenyl (1-ethyl)pentyl ketone, a precursor for the synthesis of an antifungal coumarin, 7-acetoxy-4-(1-ethyl)pentyl-3-phenyl-2H-1-benzopyran-2-one.
Assuntos
Cetonas/química , Lipase/química , Acetilação , Animais , Catálise , Pâncreas/enzimologia , Análise Espectral , Estereoisomerismo , SuínosRESUMO
A novel lipase from Aspergillus carneus has been used in organic solvents for efficient regioselective and chemoselective deacetylation of the peracetates of polyphenolic aromatic ketones, esters and amides. A reversal of regioselectivity was observed as compared with the results obtained during deacetylation with porcine pancreatic lipase (PPL).
Assuntos
Acetatos/metabolismo , Aspergillus/enzimologia , Flavonoides , Lipase/metabolismo , Acetilação , Amidas/metabolismo , Animais , Ésteres/metabolismo , Cetonas/metabolismo , Estrutura Molecular , Pâncreas/enzimologia , Peróxidos/metabolismo , Fenóis/química , Polímeros/química , Polifenóis , Solventes/metabolismo , SuínosRESUMO
Highly chemo- and regioselective de-esterification has been observed in the deacetylation of peracetylated enolic forms of polyphenolic benzyl phenyl ketones by lipase from porcine pancreas (PPL) suspended in tetrahydrofuran (THF). The enzyme selectively deacetylates the enolic acetoxy over the phenolic acetoxy group(s) and continuation of the reaction resulted, in addition the regioselective deacetylation of acetoxy function para to the nuclear carbonyl group.
