Resolution of ?2-isoxazoline-5-carboxylates by a protease fromAspergillus Oryzae providing masked synthons for enantiopure ?-aminoalcohols and related structures
作者:S. Yang、W. Hayden、H. Griengl
DOI:10.1007/bf00811865
日期:1994.4
A series of racemic DELTA2-isoxazolinecarboxylates have been synthesized and subjected to enzymatic hydrolysis by a protease from Aspergillus oryzae in a two-phase system. Out of these compounds only isoxazoline-5-carboxylates unsubstituted at C-4 were hydrolyzed. Thus, from 3-ethoxycarbonyl-, 3-methyl-, and 3-phenyl-DELTA2-isoxazoline-5-carboxylates the corresponding (R)-configurated carboxylic acids are obtained. In contrast, an additional methyl group at C-5 changes the steric course of the hydrolysis to give predominantly the (S)-acid. The enantioselectivities obtained are in the range of E = 5-35.
Chemo-enzymatic synthesis of the four stereoisomers of 4-hydroxy-4-methylglutamic acid
作者:Virgil Helaine、Jean Bolte
DOI:10.1016/s0957-4166(98)00372-3
日期:1998.11
A chemo-enzymatic synthesis of the fourstereoisomers of 4-hydroxy-4-methylglutamic acid is described. As with other glutamate analogues these compounds can serve as probes for the investigation of glutamate receptors.