Triphenylphosphine → 5-Amino-7-(5-methyl-2-oxo-[1,3]dioxol-4-ylmethoxy)-3-(2',3',5'-tri-O-acetyl-beta-D-ribofuranosyl)-thiazolo[4,5-d]pyrimidin-2-one

Participants

Reaction Steps

To a solution of triacetate 75 (1.55 g, 3.50 mmol) in THF (50 mL) at 0° C. was added polymer supported-triphenylphosphine (4.95 g, 10.50 mmol, Argonaut). To this mixture was added 4-hydroxymethyl-5-methyl-[1,3]dioxol-2-one (0.91 g, 7.00 mmol), prepared according to the procedure of Alepegiani, Syn. Comm., 22(9), 1277-82 (1992) Diethyl azodicarboxylate (0.73 ml, 4.60 mmol) was then added dropwise. The resulting mixture was stirred at room temperature for 48 h, filtered and washed with MeOH and CHCl3. The filtrate was concentrated and purified by flash column chromatography (silica, acetone/CHCl3=10-20%) to afford dioxolone derivative 85 (1.38 g, 71%) as white solid: 1H (400 MHz, d6-DMSO); δ 7.06 (s, 2H), 6.00 (d, J=4.0 Hz, 1H), 5.92 (dd, J=6.6, 4.4 Hz, 1H), 5.56 (t, J=6.4 Hz, 1H), 5.30 (s, 2H), 4.38 (dd, J=11.6, 3.6 Hz, 1H), 4.25 (t, J=3.6 Hz, 1H), 4.10 (q, J=6.0 Hz, 1H), 2.23 (s, 3H), 2.08 (s, 3H), 2.07 (s, 3H), 2.00 (s, 3H); MS (+)-ES [M+H]+ m/z 555.3. Elemental Analysis calc'd for C21H22N4O12S.Me2CO: C, 47.06; H, 4.61; N, 9.15; S, 5.23. Found: C, 47.25; H, 4.37; N, 9.53; S, 5.52.

Provenance & Evidence