Benzenesulfonic Acid → 1-[(2R,3R,4R,5R)-3,4-bis{[tert-Butyl(dimethyl)silyl]oxy}-5-(hydroxymethyl)tetrahydro-2-furanyl]-3-(4-methoxybenzyl)-2,4(1H,3H)-pyrimidinedione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Following the procedure (Myers, A. G.; Gin, D. Y.; Rogers, D. H., J. Amer. Chem. Soc., 1994, 116, 4697-4718), a suspension of sodium hydride (1.55 g, 38.75 mmole, 60% oil dispersion) in anhydrous dimethylformamide (40 ml) was cooled at 0° C. under argon, and to this mixture was added a solution of 1-[5-[bis-(4-methoxy-phenyl)-phenyl-methoxymethyl]-3,4-bis-(tert-butyl-dimethyl-silanyloxy)-tetrahydro-furan-2-yl]-1H-pyrimidine-2,4-dione (20 g, 25.8 mmole, obtained from Reference Example 1) in anhydrous dimethylformamide (35 ml) over a period of 15 min. Neat p-methoxybenzyl chloride (7 ml, 51 mmole) was added to this solution. The resulting mixture was stirred at 0° C. for 15 h under argon, and diluted with ethyl acetate (700 ml). The organic layer was washed with saturated sodium bicarbonate aqueous solution and saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated to dryness in vacuo. The oily residue was dissolved in chloroform (200 ml) and cooled at 0° C. under nitrogen. Benzenesulfonic acid (6 g, 37.93 mmole) was added portionwise, and the resulting red solution was stirred at 0° C. under nitrogen for 2 h. The mixture was diluted with ethyl acetate. The organic layer was washed with saturated sodium bicarbonate aqueous solution and saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated to dryness in vacuo. The residue was chromatographed (flash column, silica gel, methylene chloride:diethyl ether:methanol=95:3:2) to give 1-[(2R,3R,4R,5R)-3,4-bis{[tert-butyl(dimethyl)silyl]oxy}-5-(hydroxymethyl)tetrahydro-2-furanyl]-3-(4-methoxybenzyl)-2,4(1H,3H)-pyrimidinedione as white solid (9 g, 59%).

Herkunft & Nachweise