反应详情

A stirred solution of methyl 9-[(2R,3R,4R,5R)-3,4-bis{[tert-butyl(dimethyl)silyl]oxy}-5-(methoxymethyl)tetrahydro-2-furanyl]-6-[(2,2-diphenylethyl)amino]-9H-purine-2-carboxylate (7.2 g, 9.64 mmol) (preparation 14) in dry diethyl ether (150 ml) was treated with trimethyl borate (0.11 ml, 0.97 mmol) and lithium borohydride (212 mg, 9.64 mmol) and the mixture heated at reflux for 1 hr under a nitrogen atmosphere. The mixture was then cooled to room temperature, water (100 ml) carefully added and stirring continued for 10 minutes. The organic phase was separated, washed with brine and dried with anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue purified by column chromatography on silica gel eluting with a gradient system of diethyl ether:pentane (1:1) changing to diethyl ether:pentane (3:1) to afford the title compound as an oil (5.17 g). MS: 721 (MH+).

1. temperaturethe mixture heated
2. temperatureat reflux for 1 hr under a nitrogen atmosphere
3. customThe organic phase was separated
4. washwashed with brine
5. dry with materialdried with anhydrous sodium sulfate
6. customThe solvent was removed under reduced pressure
7. customthe residue purified by column chromatography on silica gel eluting with a gradient system of diethyl ether:pentane (1:1)