The chiral synthesis of (1S,3S,4S)-1-(3,4-dihydroxycyclopent-1-yl)-1H-thymi
ne (carbocyclic 5'-nor thymidine, 4) has been achieved in 5 steps from (+)-
(1R,4S)-4-hydroxy-2-cyclopenten-1-yl acetate (5) and N-3-benzoylthymine. Co
mpound 4 is viewed as a monomeric building block for poly-T-like oligomers.