5'-O-(4,4'-dimethoxytrityl)-3'-O-(N,N-diethylamino)[(N-tert-butylaminocarbonyl)methyloxy]phosphinylthymidine 、 alkaline earth salt of/the/ methylsulfuric acid 生成 N-tert-butyl-2-[[(2R,3S,5R)-3-hydroxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-[(2R,3S,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-3-yl]oxyphosphinothioyl]oxyacetamide