反应详情

4.3 g. of (1S,5R,6S)-6-formyl-2-oxabicyclo-[3,3,0]octan-3-one [see Example 9(a)], 15 ml. of triethyl orthoformate, and 40 mg. of p-toluenesulfonic acid in 15 ml. of absolute ethyl alcohol are agitated for 16 hours at 20° under argon. The mixture is then diluted with ether, shaken in succession with sodium bicarbonate solution and water, dried over magnesium sulfate, and evaporated under vacuum, thus obtaining 4.8 g. of the title compound as an oil which is completely uniform as determined by thin-layer chromatography.

1. dry with materialdried over magnesium sulfate
2. customevaporated under vacuum
3. customthus obtaining 4.8 g