| abstract |
PROBLEM TO BE SOLVED: To provide a nucleic acid derivative for treating or preventing a viral infection. As an example, a compound of either of the following formulas. (In the formula, R 1 is H or a derivative of phosphoric acid, R 2 is Cl, Br, I, methyl, trifluoromethyl, etc., and R 3 is H, D, methyl, fluoro. Methyl etc., each X is independently O or S, Z is N or CR 7 , U is O or S, W is CH 2 O, CD 2 O, CF 2 O, CH 2 CH 2 and R 7 are H, D, hydroxyl, etc.) [Selection diagram] None |