| abstract |
(57) [Problem] To provide a method for producing 2'-O-alkylated guanosine 3'-O-phosphoramidite. SOLUTION: The method for producing 2'-O-alkylated guanosine 3'-O-phosphoramidite comprises: 2,6-diamino-9- (Ribofuranosyl) purine is alkylated to produce 2,6-diamino-9- (2′-O-alkylated ribofuranosyl) purine; the 2,6-diamino-9- (2′-O-alkylated ribofuranosyl) Deamination of purine to produce a 2'-O-alkylated guanosine; protecting the 5'-hydroxyl moiety of the 2'-O-alkylated guanosine; and said 5'-protected 2'-O-alkylation A phosphinate at the 3'-position of guanosine. |