反应详情

温度

0 °C

A solution of 17.93 g (0.118 mmol) of mercaptoacetaldehyde dimer and 38.70 g (0.236 mmol) of benzoyloxyacetaldehyde in 57.3 mL (3 eq) of pyridine was heated until all the solid dissolved. After cooling, 300 mL of anhydrous methylene chloride were added and the mixture was cooled at 0° C. for ca. 30 minutes. To this solution at 0° C., was slowly added a solution of methylchloroformate (57.3 mL, 0.71 mmol) in 80 mL of methylene chloride. The mixture was stirred for 12 hrs and diluted with ca. 200 mL of methylene chloride and washed several times with brine to remove pyridinium salt and then the organic layer was washed with water. The organic layer was dries over magnesium sulphate at 0° C. and then filtered. Residual pyridine was removed in vacuo and the organic residue was purified by flash chromatography using hexanes:ethyl acetate (2:1) as eluent to yield a mixture of 2:1 trans:cis carbonates (56.3 g, 80%).

1. dissolutiondissolved
2. temperatureAfter cooling
3. washwashed several times with brine
4. customto remove pyridinium salt
5. washthe organic layer was washed with water
6. customat 0° C.
7. filtrationfiltered
8. customResidual pyridine was removed in vacuo
9. customthe organic residue was purified by flash chromatography
10. customto yield
11. additiona mixture of 2:1 trans