| abstract |
Compounds of the formulae I and Ia and their racemates <IMAGE> (I) <IMAGE> (Ia) in which A is -CH2- or -CH2CH2-, R1 is hydrogen or a protective group, R2 is hydrogen or a protective group or a radical forming a phosphorus-containing nucleotide bridge group and B is a purine or pyrimidine radical or an analogue thereof, can be used as antiviral active ingredients or for the preparation of biologically active oligonucleotides. |