2(S)-(acetoxymethyl)-4-[3,4-dihydro-2-oxo-4-amino-1(2H)-pyrimidinyl]-2,5-dihydrofuran

2(S)-(acetyloxymethyl)-4-[3,4-dihydro-2,4-dioxo-1(2H)-pyrimidinyl]-2,5-dihydrofuran

1,4-anhydro-2-amino-2-deoxy-3,5-O-(1,1,3,3-tetraisopropyl-1,3-disiloxanediyl)-D-arabinitol

2-deoxy-1,4-O2,3-anhydro-2-<3,4-dihydro-4-oxo-5-methyl-1(2H)-pyrimidinyl>-5-O-(tert-butyldimethylsilyl)-D-lyxitol