反应详情

74 g of ethyl 4-formyl-3,3-dimethylbutanoate, prepared in Example 91, are dissolved in 450 ml of anhydrous toluene in the presence of 0.5 g of paratoluenesulfonic acid and 26.7 g of ethylene glycol. The mixture is heated to the reflux temperature and the water formed during the reaction is removed by means of a Dean-Stark apparatus. After refluxing for two hours, the solvent is evaporated off under vacuum and the residue is distilled to give 86.7 g of ethyl 4-(dioxolan-2-yl)-3,3-dimethylbutanoate in the form of a liquid with a boiling point b.p. of 138°-140° C.

1. temperatureThe mixture is heated to the reflux temperature
2. customis removed by means of a Dean-Stark apparatus
3. temperatureAfter refluxing for two hours
4. customthe solvent is evaporated off under vacuum
5. distillationthe residue is distilled