초록
<P>A new method for the chemo-enzymatic Baeyer–Villiger oxidation of cyclic ketones to lactones has been developed. The influence of reaction parameters and the structure of various ionic liquids were studied. Free <I>Candida antarctica</I> lipase B or Novozyme-435 suspended in an ionic liquid was used as the catalytic phase. The reaction was carried out under mild conditions at room temperature using 30% aq. H<SUB>2</SUB>O<SUB>2</SUB> as the oxidation agent. 1-Butyl-3-methyl bistriflimide was the most effective ionic liquid and increased the reaction rate compared to toluene. Lipase exhibited good stability, and the ionic liquid could be easily reused. Therefore, a general chemo-enzymatic method for the oxidation of cyclohexanones and cyclobutanones to obtain adequate lactones in high yields (79–95%) has been proposed.</P><BR><BR><P>Graphic Abstract</P><P>A new method for the synthesis of lactones in the presence of ionic liquids and lipase has been developed.<BR><IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4nj01976h'><BR></P>