In the presence of methyl, tert-butyl, or (−)-menthyl esters of 2-oxocyclopentanecarboxylic acids Jacobsen-type complexes of cobalt (II) and manganese (III) form active catalysts for alkene epoxidation using molecular oxygen. Alkyl-1-hydroxy-2- oxocyclopentanecarboxylates and 1-alkyl-2-oxo-hexanedicarboxylic acids are formed as co- oxidation products. The (−)-menthyl/cobalt system is selective for epoxide production but ...
[Schaus, Scott E.; Brandes, Bridget D.; Larrow, Jay F.; Tokunaga, Makoto; Hansen, Karl B.; Gould, Alexandra E.; Furrow, Michael E.; Jacobsen, Eric N. Journal of the American Chemical Society, 2002 , vol. 124, # 7 p. 1307 - 1315]