反应详情

To a solution of crude cis-4-(butoxycarbonyl)cyclohexanecarboxylic acid (36.5 g) in dry tetrahydrofuran (300 ml) under nitrogen cooled in an ice-bath was added dropwise over 20 minutes 1.0M borane in tetrahydrofuran (150 ml, 150 mmol). The ice-bath was removed and the solution was stirred at ambient temperature for three hours. Water (200 ml) was added dropwise to the stirred solution, the mixture stirred an additional 15 minutes, and potassium carbonate (7.5 g) was added. The mixture was diluted with ether (500 ml) and the layers were separated. The organic layer was washed with brine (100 ml), dried (sodium sulfate), filtered, and the solvent was evaporated under reduced pressure to give crude product (32.38 g) as a pale yellow oil. The crude product was purified by flash column chromatography on silica gel, eluting with ethyl acetate/hexane (10:90 increasing to 50:50). The first compound to elute was dibutyl cis-cyclohexane-1,4-dicarboxylate (MS.: 285.3 (M+1), 3.92 g, 10%), followed by butyl cis-4-(hydroxymethyl)-cyclohexane carboxylate (23.97 g, 75%), as a pale yellow oil: 1H NMR (CDCl3) 4.08 (2H, t, J 7 Hz), 3.50 (1H, t, J 7 Hz), 2.56 (1H, m), 2.02 (2H, m), 1.52-1.65 (7H, m), 1.26-1.41 (5H, m), 0.94 (3H, t, J 7 Hz). MS.: 215.3 (M+1).

1. customThe ice-bath was removed
2. additionWater (200 ml) was added dropwise to the stirred solution
3. stirringthe mixture stirred an additional 15 minutes
4. additionpotassium carbonate (7.5 g) was added
5. additionThe mixture was diluted with ether (500 ml)
6. customthe layers were separated
7. washThe organic layer was washed with brine (100 ml)
8. dry with materialdried (sodium sulfate)
9. filtrationfiltered
10. customthe solvent was evaporated under reduced pressure