反应详情

To a mixture of 1-[9-(1-carboxycyclopentyl)-5-oxononyl]-1-cyclopentanecarboxylic acid (4.70 g, 11.5 mmol) in iPrOH (30 mL) and H2O (30 mL) was added NaOH (1.10 g, 27 mmol). To the resulting clear solution, NaBH4 (0.242 g, 6.4 mmol) was added. After 23 h, TLC analysis revealed the reaction to be incomplete, and an additional portion of NaBH4 (0.036 g, 0.95 mmol) was added. Stirring was continued for 17 h and then, the reaction mixture was concentrated in vacuo. The remaining residue was dissolved in H2O (80 mL) and washed with Et2O (20 mL). The aqueous layer was acidified with aqueous HCl (6M, 15 mL) and then extracted with Et2O (3×50 mL). The combined organic layers were washed with brine (2×50 mL), dried (Na2SO4) and concentrated in vacuo to give 1-[9-(1-carboxycyclopentyl)-5-hydroxynonyl]-1-cyclo-pentanecarboxylic acid (4.45 g, 98%, contains 7% (w/w) Et2O) as a thick, slightly hazy, light yellow oil. 1H NMR (CDCl3): δ=3.56 (br s, 1H), 2.16-2.10 (m, 4H), 1.65-1.60 (m, 12H), 1.51-1.18 (m, 16H). 13C NMR (CDCl3): δ=184.1 (2×), 71.1, 54.2 (2×), 39.4 (2×), 37.1 (2×), 36.1 (2×), 35.7 (2×), 26.0 (2×), 25.8 (2×), 25.03 (2×), 25.00 (2×).

1. customthe reaction
2. waitwas continued for 17 h
3. concentrationthe reaction mixture was concentrated in vacuo
4. dissolutionThe remaining residue was dissolved in H2O (80 mL)
5. washwashed with Et2O (20 mL)
6. extractionextracted with Et2O (3×50 mL)
7. washThe combined organic layers were washed with brine (2×50 mL)
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated in vacuo