COSOLVENT ENHANCEMENT OF ENANTIOSELECTIVITY IN LIPASE-CATALYZED HYDROLYSIS OF RACEMIC ESTERS - A PROCESS FOR PRODUCTION OF HOMOCHIRAL C-3 BUILDING-BLOCKS USING LIPASE-B FROM CANDIDA-ANTARCTICA
Tv. Hansen et al., COSOLVENT ENHANCEMENT OF ENANTIOSELECTIVITY IN LIPASE-CATALYZED HYDROLYSIS OF RACEMIC ESTERS - A PROCESS FOR PRODUCTION OF HOMOCHIRAL C-3 BUILDING-BLOCKS USING LIPASE-B FROM CANDIDA-ANTARCTICA, Tetrahedron : asymmetry, 6(2), 1995, pp. 499-504
Lipase-catalysed hydrolysis of butanoates of 3-methoxy-1-(phenylmethox
y)-2-propanol and 3-chloro-1-(phenylmethoxy)-2-propanol with various l
ipases gave low enantioselectivity, E. By additon of water miscible or
ganic cosolvents, in particular tert-butanol and acetone, the E-value
was raised from 7 to 220 for the useful chloro derivative. This findin
g has led to proposal of a process for production of homochiral C-3 sy
nthons such as both enantiomers of phenylmethyl glycidyl ether startin
g from racemic epichlorohydrin. NMR studies of lipase B from Candida a
ntarctica show that the conformation most likely is not changed upon a
ddition of up to 50% acetone. Nuclear Overhauser effects were observed
upon irradiation of the phenyl protons of the substrate only in the p
resence of enzyme thus indicating an interaction between the two.