| abstract |
The invention relates to new sulfonic acid esters of the formula wherein R 1 is unsubstituted or substituted by C 1 -C 7 alkyl, C 5 -C 6 cycloalkyl, or unsubstituted or substituted phenyl, R 2 is C 1 -C 7 alkyl, R 3 is phenyl which is represented by Halogen or nitro is substituted, and the symbol * a carbon atom indicates that either the majority of molecules are in the S configuration or the majority of the molecules are in the R configuration.n n n They can be prepared by enantioselective reduction of 4- R 1 -substituted-α-oxo-butyric acid compounds and subsequent conversion of the a-hydroxy group obtained into the group-OSO 2 -R 3 . The compounds of the formula are suitable as intermediates for the preparation of ACE inhibitors or their precursors. |