| abstract |
PROBLEM TO BE SOLVED: To provide an efficient method for producing a pharmaceutical compound (A) having a VLA-4 inhibitory action and high safety, and a production intermediate thereof. [MEANS FOR SOLVING PROBLEMS] A 1,1-disubstituted ethyl ester (1) of trans-type 4-hydroxycyclohexanecarboxylic acid (1) as a starting material, via an important intermediate (13) produced by a trans and stereospecific pyrrolidine ring construction method The present invention was completed by finding a method for producing a pharmaceutical compound (A). [Chemical 1] [Wherein, R 1a and R 1b each independently represent a lower alkyl group, an optionally substituted phenyl group, or an optionally substituted benzyl group, and R 6 represents A lower alkyl group is meant. ] [Selection figure] None |