反应详情

Methyl 2-hydroxy-4-octadecenoate (8.21 g, 0.026 mol, 1.0 eq) is heated under reflux with a large excess of sodium hydroxide (8.4 g, 0.21 mol, 8.1 eq) in water (20 ml) and methanol (20 ml) for 1 hour. After cooling down to room temperature, the mixture is washed with hexane (50 ml) and the organic phase separated. The clear aqueous layer is acidified to pH 1 with concentrated hydrochloric acid and the resultant mixture is extracted with diethylether (3×50 ml), the combined organic layers being washed with brine (50 ml) dried over anhydrous magnesium sulphate and evaporated to give a white solid. This is recrystallised from ethyl acetate/hexane to give the product acid (5) as white needles, 6.35 g (81%), mp 78-79.5° C.

1. washthe mixture is washed with hexane (50 ml)
2. customthe organic phase separated
3. extractionthe resultant mixture is extracted with diethylether (3×50 ml)
4. washthe combined organic layers being washed with brine (50 ml)
5. dry with materialdried over anhydrous magnesium sulphate
6. customevaporated
7. customto give a white solid
8. customThis is recrystallised from ethyl acetate/hexane