反应详情

trans-7-(4-Hydroxycyclohexyl)heptanoic acid (6.5 g) and p-toluenesulfonic acid (15 mg) are stirred in acetic anhydride (32.5 ml) at 60°-70° C. for 1.5 hours. The excess acetic anhydride is distilled off under reduced pressure, followed by addition of water (90 ml), and the mixture is stirred for 3 days. The resulting crystalline precipitate is collected by filtration and recrystallized from ethyl acetate-hexane to give 6.5 g of trans-7-(4-acetoxycyclohexyl)heptanoic acid as colorless needless, m.p. 66°-68° C.

1. distillationThe excess acetic anhydride is distilled off under reduced pressure
2. additionfollowed by addition of water (90 ml)
3. filtrationThe resulting crystalline precipitate is collected by filtration
4. customrecrystallized from ethyl acetate-hexane