Novel sulfonic acid esters and their preparation

A process for the preparation of a compound of the formula ##STR26## wherein R.sup.1 is (a) C.sub.5-6 cycloalkyl which is unsubstituted or substituted by C.sub.1-7 alkyl or (b) phenyl which is unsubstituted or substituted by at least one substituent selected from C.sub.1-7 alkyl, hydroxy, C.sub.1-7 alkoxy, C.sub.1-7 alkanoyloxy, fluorine, C.sub.1-7 alkylenedioxy, amino, C.sub.1-7 alkylamino, di(C.sub.1-7 alkyl)amino, C.sub.1-7 alkanoylamino, carbamoyl, C.sub.1-7 alkyl carbamoyl, di(C.sub.1-7 alkyl) carbamoyl, C.sub.1-7 alkylsulfonylamino, sulfamoyl, C.sub.1-7 alkylsulfamoyl, di(C.sub.1-7 alkyl)sulfamoyl, C.sub.1-7 haloalkyl, C.sub.1-7 hydroxyalkyl, and C.sub.1-7 aminoalkyl;

• R.sup.2 is C.sub.1-7 alkyl;
• and the asterisk denotes a carbon atom that is either present in the preponderant number of molecules in the S configuration or in the preponderant number of molecules in the R configuration;
• and
• (i) R' is hydrogen or C.sub.1-7 alkyl;
• and R is a group of the formulae ##STR27## or (ii) R' is hydrogen and R is hydrogen;
• 1-phenyl C.sub.1-7 alkyl or 1-naphthyl-C.sub.1-7 alkyl;
• in which
• R.sub.2 is hydrogen or C.sub.1-7 alkyl;
• R.sub.3 and R.sub.4 are each independently hydrogen, C.sub.1-7 alkyl, C.sub.1-7 alkoxy, C.sub.1-7 alkanoyloxy, hydroxy, halogen, or trifluoromethyl or both R.sub.3 and R.sub.4 together are C.sub.1-7 alkylenedioxy;
• R.sub.7 together with the carbonyl group to which it is attached is carboxy or a functionally modified carboxy;
• and
• X is oxo, two hydrogen atoms, or one hydrogen atom and one hydroxyl group which comprises alkylating a compound of the formula ##STR28## under inversion, with a compound of the formula ##STR29## wherein R', R, R.sup.1, R.sup.2 and the asterisk are as defined above and R.sup.3 is phenyl which is substituted by halogen or nitro.

A process of converting a compound of the formula ##STR32## into a compound of the formula ##STR33## wherein R.sup.1 is (a) C.sub.5-6 cycloalkyl which is unsubstituted or substituted by C.sub.1-7 alkyl or (b) phenyl which is unsubstituted or substituted by at least one substituent selected from C.sub.1-7 alkyl, hydroxy, C.sub.1-7 alkoxy, C.sub.1-7 alkanoyloxy, fluorine, C.sub.1-7 alkylenedioxy, amino, C.sub.1-7 alkylamino, di(C.sub.1-7 alkyl)amino, C.sub.1-7 alkanoylamino, carbamoyl, C.sub.1-7 alkyl carbamoyl, di(C.sub.1-7 alkyl) carbamoyl, C.sub.1-7 alkylsulfonylamino, sulfamoyl, C.sub.1-7 alkylsulfamoyl, di(C.sub.1-7 alkyl)sulfamoyl, C.sub.1-7 haloalkyl, C.sub.1-7 hydroxyalkyl, and C.sub.1-7 aminoalkyl;

• R.sup.2 is C.sub.1-7 alkyl;
• the asterisk denotes a carbon atom that is either present in the preponderant number of molecules in the S configuration or in the preponderant number of molecules in the R configuration;
• R' is hydrogen or C.sub.1-7 alkyl;
• R.sub.2 is hydrogen or C.sub.1-7 alkyl;
• R.sub.3 and R.sub.4 are each independently hydrogen, C.sub.1-7 alkyl, C.sub.1-7 alkoxy, C.sub.1-7 alkanoyloxy, hydroxy, halogen, or CF.sub.3 or both R.sub.3 and R.sub.4 together are C.sub.1-7 alkylene dioxy;
• R.sub.7 together with the carbonyl group to which it is attached is carboxy or functionally modified carboxy;
• and
• X is two hydrogens, comprising hydrogenolysing said compounds of formula VIb.