反应详情

This reaction was repeated on a larger scale with the sodium salt of 2-chloro-6-(2-propylimidazol-1-yl)purine (1.54 g, 5.87 mmol) in dried CH3CN (100 mL) treated with 2-deoxy-3,5-di-O-(p-toluoyl)-α-D-erythro-pentofuranosyl chloride (3.74 g, 9.62 mmol) in CH2Cl2 (100 mL) by general method 2 for 5 h (reaction complete, TLC). Sampling at different reaction times showed no α-nucleoside by 1H NMR (500 MHz). Volatiles were evaporated, and the residue was dissolved in CH2Cl2. The solution was washed (H2O) and dried (Na2SO4), and volatiles were evaporated in vacuo. The residue was chromatographed (EtOAc/hexanes, 1:1→7:3) to give 2-chloro-9-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-6-(2-propylimidazol-1-yl)purine (3.42 g, 95%). Recrystallization from EtOAc gave the β-anomer (2.75 g, 76%).

1. custom(reaction complete, TLC)
2. aliquotSampling at different reaction times
3. customVolatiles were evaporated
4. dissolutionthe residue was dissolved in CH2Cl2
5. washThe solution was washed (H2O)
6. dry with materialdried (Na2SO4), and volatiles
7. customwere evaporated in vacuo
8. customThe residue was chromatographed (EtOAc/hexanes, 1:1→7:3)