Pyridine → ((3aR,5R,6S,6aR)-6-hydroxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxol-5-yl)methyl benzoate

Temperatur

0 °C

A solution of 1,2-O-isopropylidene-α-D-xylofuranose 1 (30 g, 0.15 mol) in 360 mL of CH2Cl2 was cooled to 0° C. and to it was added 20 mL (0.23 mol) of pyridine and a catalytic amount (1.0 g) of N,N-dimethylaminopyridine. The resulting mixture was stirred at 0° C. for 10 min, at which time 20 mL (0.17 mol) benzoyl chloride was added to it dropwise over a period of 30 min. The reaction mixture was stirred at 0° C. for an additional 30 min and then quenched by the addition of 200 mL a saturated solution of NH4Cl. The reaction was allowed to warm to room temperature, the layers were separated, and the aqueous layer was extracted with 3×50 mL of CH2Cl2. The combined organic extracts were washed with 3×50 mL of a 10% aqueous solution of CuSO4, 2×50 mL of water and brine. The organic solution was dried over anhydrous MgSO4, filtered and concentrated. The crude product mixture was purified by chromatography on silica gel to afford 44.3 g (95% yield) of 2 as a colorless liquid: Rf 0.54 (60% EtOAc/hexane); 1H-NMR (CDCl3) δ8.03 (m, 2H), 7.40-7.68 (m, 3H), 5.97 (d, 1H, J=3.6 Hz), 4.80 (m, 1H), 4.61 (d, 1H, J=3.4 Hz), 4.37 (m, 2H), 4.20 (s, broad, 1H), 3.35 (broad, 1H), 1.50 (s, 3H), 1.32 (s, 3H).

1. additionwas added to it dropwise over a period of 30 min
2. customquenched by the addition of 200 mL a saturated solution of NH4Cl
3. temperatureto warm to room temperature
4. customthe layers were separated
5. extractionthe aqueous layer was extracted with 3×50 mL of CH2Cl2
6. washThe combined organic extracts were washed with 3×50 mL of a 10% aqueous solution of CuSO4, 2×50 mL of water and brine
7. dry with materialThe organic solution was dried over anhydrous MgSO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude product mixture was purified by chromatography on silica gel

ORD-Eintrag

ord-d2ff8d6aa91449318ddd8af41f2a797f

Quelldatensatz

uspto-grants-2000_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06025392