The effect of ethanol on the kinetics of lipase-mediated enantioselective esterification of 4-methyloctanoic acid and the hydrolysis of its ethyl ester.
The Novozym 435(R) catalyzed esterification and hydrolysis reactions of 4-methyloctanoic acid (ethyl ester) were investigated. In both the hydrolysis and esterification reactions, the increase of ethanol concentration led to an increase in enantiomeric ratio (E). For hydrolysis of the ethyl ester, the E-value increased from 5.5 [0% (v/v) EtOH] up to 12 [20% (v/v) EtOH]. In case of esterification, the E-value was already 16 [14% (v/v) EtOH] and rose to 57 [73% (v/v) EtOH]. When combining these results of esterification and hydrolysis, an enantiomeric ratio of 350 can be estimated for the sequential kinetic resolution of 4-methyloctanoic acid. In this way, enantiopure 4-methyloctanoic acid could be obtained after two consecutive reaction steps.
Heinsman
N W
NW
Wageningen University, Department of Food Technology and Nutritional Sciences, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
Valente
A M
AM
Smienk
H G
HG
van der Padt
A
A
Franssen
M C
MC
de Groot
A
A
van 't Riet
K
K
D002210:Caprylates / Q000378:metabolism*; D004800:Enzymes, Immobilized; D004951:Esterification / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D005656:Fungal Proteins; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D008968:Molecular Conformation; D013696:Temperature
D002210:Caprylates; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D000431:Ethanol; C103470:ethyl 4-methyloctanoate; C093667:Novozyme 435; D008049:Lipase