反应详情

85.3 g of 2-ethoxycarbonyl-2,5-dimethyl-4-hexenoic acid ethyl ester is dissolved in 645 ml of dimethyl sulfoxide and combined in succession with 29.7 g of lithium chloride and 6.3 ml of distilled water. Then the reaction mixture is heated for a total of 13 hours to 200° C. and then--after having been allowed to cool down--is poured on 1 liter of ice water. The aqueous phase is extracted three times with respectively 500 ml of methylene chloride. The combined organic extracts are then washed twice with water, dried over magnesium sulfate, concentrated with the aid of a forced-circulation evaporator, and distilled under vacuum, thus isolating 53.1 g, bp13 75°-78° C.

1. temperatureThen the reaction mixture is heated for a total of 13 hours to 200° C.
2. temperatureto cool down
3. extractionThe aqueous phase is extracted three times with respectively 500 ml of methylene chloride
4. washThe combined organic extracts are then washed twice with water
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated with the aid of a forced-circulation evaporator
7. distillationdistilled under vacuum
8. customthus isolating 53.1 g, bp13 75°-78° C.