Process for preparing a compound of the general formula I wherein R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, R 4 is selected from C 1 -C 6 -alkanoyl, and X is selected from C 1 -C 20 -alkyl and C 2 -C 20 -alkenyl, comprising the following steps: a) providing a quinone compound of the general formula II, wherein R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, b) catalytic hydrogenation of the quinone compound of formula II provided in step a) in the presence of hydrogen, a hydrogenation catalyst and in the presence of a carbonate solvent to obtain a hydroquinone compound of the general formula III, wherein R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, c) reacting the hydroquinone compound III provided in step b) with an unsaturated compound of the general formula IV.a or IV.b wherein X is selected from C 1 -C 20 -alkyl and C 2 -C 20 -alkenyl, Y is selected from OH, halogen, -O-R 11, -S-R 12 and -SO 2 -R 12, R 11 is selected from C 1 -C 4 -alkyl, C 1 -C 4 -alkanoyl and trifluoroacetyl, and R 12 is selected from C 1 -C 6 -alkyl, trifluoromethyl and phenyl, where phenyl is unsubstituted or substituted with 1, 2, 3, 4 or 5 radicals selected from halogen and methyl, in the presence of a condensation catalyst and in the presence of a carbonate solvent, and d) reacting the condensation product obtained in step c) with a C 2 -C 7 -carboxylic acid or with a C 2 -C 7 -carboxylic acid anhydride in the presence of an esterification catalyst and in the presence of a carbonate solvent, or reacting the condensation product obtained in step c) with an activated C 2 -C 7 -carboxylic acid in the presence of a base and in the presence of a carbonate solvent, where the reaction mixture obtained in step b) is used directly in the reaction in step c) after removal of the hydrogenation catalyst, where steps b), c) and d) are carried out in the same carbonate solvent, and where the carbonate solvent is selected from at least one organic carbonate and from mixtures, consisting of at least one organic carbonate and at least one apolar hydrocarbon solvent. R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, R 4 is selected from C 1 -C 6 -alkanoyl, and X is selected from C 1 -C 20 -alkyl and C 2 -C 20 -alkenyl, a) providing a quinone compound of the general formula II, wherein R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, b) catalytic hydrogenation of the quinone compound of formula II provided in step a) in the presence of hydrogen, a hydrogenation catalyst and in the presence of a carbonate solvent to obtain a hydroquinone compound of the general formula III, wherein R 1, R 2 and R 3 independently of each other are selected from hydrogen and methyl, c) reacting the hydroquinone compound III provided in step b) with an unsaturated compound of the general formula IV.a or IV.b wherein X is selected from C 1 -C 20 -alkyl and C 2 -C 20 -alkenyl, Y is selected from OH, halogen, -O-R 11, -S-R 12 and -SO 2 -R 12, R 11 is selected from C 1 -C 4 -alkyl, C 1 -C 4 -alkanoyl and trifluoroacetyl, and R 12 is selected from C 1 -C 6 -alkyl, trifluoromethyl and phenyl, where phenyl is unsubstituted or substituted with 1, 2, 3, 4 or 5 radicals selected from halogen and methyl, in the presence of a condensation catalyst and in the presence of a carbonate solvent, and X is selected from C 1 -C 20 -alkyl and C 2 -C 20 -alkenyl, Y is selected from OH, halogen, -O-R 11, -S-R 12 and -SO 2 -R 12, R 11 is selected from C 1 -C 4 -alkyl, C 1 -C 4 -alkanoyl and trifluoroacetyl, and R 12 is selected from C 1 -C 6 -alkyl, trifluoromethyl and phenyl, where phenyl is unsubstituted or substituted with 1, 2, 3, 4 or 5 radicals selected from halogen and methyl, d) reacting the condensation product obtained in step c) with a C 2 -C 7 -carboxylic acid or with a C 2 -C 7 -carboxylic acid anhydride in the presence of an esterification catalyst and in the presence of a carbonate solvent, where the reaction mixture obtained in step b) is used directly in the reaction in step c) after removal of the hydrogenation catalyst, where steps b), c) and d) are carried out in the same carbonate solvent, and where the carbonate solvent is selected from at least one organic carbonate and from mixtures, consisting of at least one organic carbonate and at least one apolar hydrocarbon solvent.