反应详情

A solution of methyl (1R,4S)-4-(2,5-dimethyl-1H-pyrrol-1-yl)-1-ethylcyclopent-2-ene-1-carboxylate (12.94 g, 52.3 mmol) in methanol (100 ml) was treated with 2.5 N NaOH (30 ml, 75.0 mmol) and stirred at room temperature. After 15 hours more 2.5 N NaOH (10 ml, 25.0 mmol) was added and the reaction was stirred for an additional four days. The methanol was removed under reduced pressure and the residue partitioned between diethyl ether and water. The layers were separated and the aqueous was acidified with 4 N HCl, extracted twice with ethyl acetate, washed with brine, dried over MgSO4, and concentrated under reduced pressure to give (1R,4S)-4-(2,5-dimethyl-1H-pyrrol-1-yl)-1-ethylcyclopent-2-ene-1 carboxylic acid as a brown oil (11.83 g, 97%). 1H NMR (400 MHz, CDCl3) δ ppm 5.98-5.96 (2H), 5.73 (2H), 5.30-5.26 (1H), 2.47-2.35 (2H), 2.20 (6H), 1.82-1.77 (2H), 0.96-0.92 (3H).

1. stirringthe reaction was stirred for an additional four days
2. customThe methanol was removed under reduced pressure
3. customthe residue partitioned between diethyl ether and water
4. customThe layers were separated
5. extractionextracted twice with ethyl acetate
6. washwashed with brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated under reduced pressure