反应详情

2.5 g (0.1 mol) of lithium hydroxide are added at 0° C. to 10 g (0.07 mol) of ethyl trans-4-methyl-2,4-pentadienecarboxylate, dissolved in a solvent mixture of 75 ml of methanol, 17 ml of tetrahydrofuran and 2.5 ml of water, and the mixture is stirred for 20 hours at room temperature. After the mixture has been diluted with 200 ml of water, it is extracted once using diethyl ether, and a pH of 1 is established in the aqueous phase at 0° C. using concentrated hydrochloric acid. The mixture is extracted using diethyl ether, the combined organic phases are washed several times with water and saturated sodium chloride solution, and, after drying and concentrating, 6.1 g (76% of theory) of trans-4-methyl-2,4-pentadienecarboxylic acid are obtained. ##STR208##

1. extractionis extracted once using diethyl ether
2. customis established in the aqueous phase at 0° C.
3. extractionThe mixture is extracted
4. washthe combined organic phases are washed several times with water and saturated sodium chloride solution
5. customafter drying
6. concentrationconcentrating