反应 #51524

反应方程式

sodium cyanoborohydride

2′-O-allyl-3′,5′-bis(tert-butyl diphenylsilyl)guanosine

4-methyl morpholine-N-oxide

sodium bicarbonate

→

title compound

收率 72.0%

2′-O-(2-hydroxyethyl)-3′,5′-bis(tert-butyldiphenylsilyl)guanosine

收率 72.0%

溶剂

CH2Cl2

acetone

反应条件

后处理

1. 1
   其他Reaction volume
2. 2
   浓缩was concentrated to half and ethyl acetate (50 mL)
3. 3
   workup.ADDITIONwas added
4. 4
   洗涤It was then washed with water (30 mL) and brine (30 mL)
5. 5
   干燥Ethyl acetate layer was dried over anhydrous Na2SO4
6. 6
   其他evaporated to dryness
7. 7
   workup.DISSOLUTIONResidue was then dissolved in CH2Cl2
8. 8
   workup.ADDITIONwas added
9. 9
   workup.STIRRINGstirred with the reaction mixture for 30 min
10. 10
    过滤The reaction mixture was filtered
11. 11
    洗涤silica was washed thoroughly with CH2Cl2
12. 12
    其他Combined CH2Cl2 layer was evaporated to dryness
13. 13
    workup.DISSOLUTIONResidue was then dissolved
14. 14
    workup.DISSOLUTIONin dissolved in 1M pyridinium-p-toluene sulfonate (PPTS) in dry MeOH (99.5 mL) under inert atmosphere
15. 15
    workup.STIRRINGstirred at room temperature for 4 hr
16. 16
    萃取extracted with ethyl acetate (2×50 mL)
17. 17
    干燥Ethyl acetate layer was dried over anhydrous Na2SO4
18. 18
    其他evaporated to dryness
19. 19
    洗涤eluted with 10% MeOH in CH2Cl2

实验过程

2′-O-allyl-3′,5′-bis(tert-butyl diphenylsilyl)guanosine (9 g, 11.23 mmol) was dissolved in CH2Cl2 (80 mL). To the clear solution acetone (50 mL), 4-methyl morpholine-N-oxide (1.89 g, 16.17 mmol) was added. The reaction flask was protected from light. Thus 4% aqueous solution of osmium tetroxide was added and the reaction mixture was stirred at room temperature for 6 hr. Reaction volume was concentrated to half and ethyl acetate (50 mL) was added. It was then washed with water (30 mL) and brine (30 mL). Ethyl acetate layer was dried over anhydrous Na2SO4 and evaporated to dryness. Residue was then dissolved in CH2Cl2 and NaIO4 adsorbed on silica (21.17 g, 2 g/mmol) was added and stirred with the reaction mixture for 30 min. The reaction mixture was filtered and silica was washed thoroughly with CH2Cl2. Combined CH2Cl2 layer was evaporated to dryness. Residue was then dissolved in dissolved in 1M pyridinium-p-toluene sulfonate (PPTS) in dry MeOH (99.5 mL) under inert atmosphere. To the clear solution sodium cyanoborohydride (1.14 g, 18.2 mmol) was added and stirred at room temperature for 4 hr. 5% aqueous sodium bicarbonate (50 mL) was added to the reaction mixture slowly and extracted with ethyl acetate (2×50 mL). Ethyl acetate layer was dried over anhydrous Na2SO4 and evaporated to dryness. Residue placed on a flash column and eluted with 10% MeOH in CH2Cl2 to givet the title compound (6.46 g, 72% yield). MS (Electrospray−) m/e 802 (M−H⊕)

来源