wherein R0, Q, Q??? and X are as defined in claim 1, are precursor groups thereof, or are protected by protective groups R1???, R1???, R1?????? and R1??????, which protective groups are independently from each other a hydrogen atom; R1, which is as defined in claim 1; a precursor group; or protective group; and Y is a nucleophilically substitutable leaving group or a hydroxyl group, with a compoun