| abstract |
A method is provided for processing a solution having optical isomers .to obtain a (2R,38) target isomer: wherein P1 is H or a hydroxyl protecting group, R1 is H, an alkyl group, an olefinic group or an aromatic group, and R2 is H or R3CO, where R3 is an alkyl group, an olefinic group, an aromatic group, an O-alkyl group, an 0- olefinic group or an O-aromatic group, provided that R<1> is not H when R<3> is Ph and P<1> is H. The method includes passing the solution through a chromatographic stationary phase, such as S,S Whelk-O, that has a greater affinity for one of the target isomer and an optical isomer thereof. A portion of the solution with the target isomer is then collected. The solution may be a racemic mixture of (+/-)-N-CBZ-3-phenylisoserine ethyl ester. |