反应详情

By using the literature known procedure (Barrett, A. G. M.; Lebold, S. A., J. Org. Chem., 1990, 55, 3853), to a solution of dry pyridine (48.5 ml) in anhydrous methylene chloride (700 ml) was added chromium oxide (30 g, 0.3 mole) portionwise under nitrogen. During this procedure the reaction mixture was kept at room temperature by occasional cooling with an ice-water bath. To this dark red solution was added a solution of [(3aR,4R,6aR)-6-methoxy-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl]methanol (5 g, 24.48 mmole, obtained from Reference Example 35) in methylene chloride (100 ml) under nitrogen. The resulting mixture was stirred at room temperature for 30 min, and poured into a cold aqueous solution of saturated sodium bicarbonate. The organic layer was separated and the aqueous layer was extracted with methylene chloride. The combined extracts were washed well with saturated sodium chloride solution until the color of the organic layer turned yellow, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was dissolved in benzene, and the solvent was removed in vacuo. This procedure was repeated several more times, to give [(3aR,4R,6aR)-6-methoxy-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbaldehyde (2.8 g, 56.6%) as a yellow amorphous solid. The aldehyde was dissolved in benzene and stored in the freezer under argon.

1. customwas kept at room temperature
2. temperatureby occasional cooling with an ice-water bath
3. customThe organic layer was separated
4. extractionthe aqueous layer was extracted with methylene chloride
5. washThe combined extracts were washed well with saturated sodium chloride solution until the color of the organic layer
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. dissolutionThe residue was dissolved in benzene
10. customthe solvent was removed in vacuo