Patent ID: 8252919

Claim:
A method for producing a 2′-hydroxy-protected ribonucleoside derivative, wherein the 2′-hydroxy-protected ribonucleoside derivative is represented by the formula (2): wherein, R 1 is a hydrogen atom or a protective group for a hydroxy group; R 2 is an acyl or a carbamoyl group; B is 9-adeninyl, 9-guaninyl, 1-cytosinyl, 1-uracilyl or a protected derivative thereof, represented by the following formula: wherein, R 3 is a hydrogen atom or a protective group for an amino group; comprising a step of reacting a ribonucleoside represented by the formula (1): wherein, R 1 and B mean the same as the above, with an acylating or a carbamoylating reagent in the presence of a copper complex consisting of a copper compound and an optically active ligand, to regioselectively introduce an acyl or a carbamoyl group in place of the 2′-hydroxy group.