| abstract |
The present invention is a novel nucleoside or nucleotide that can be used as a material for synthesizing nucleic acid pharmaceuticals, represented by the following formula (I): (Where Y 1 -Y 2 is S (═O) 2 —NR 6 , NR 6 —S (═O) 2 or the like, R 6 is a hydrogen atom, substituted or unsubstituted alkyl, and the like, Bx is the nucleobase moiety, Z 1 and Z 2 are each independently a hydrogen atom, a hydroxyl protecting group or a reactive phosphorus group, R 1 to R 5 are each independently a hydrogen atom, halogen, cyano, substituted or unsubstituted alkyl, n is an integer of 0 to 3) Or a salt thereof. |