反应详情

A stirred solution of (S)-1-(benzyloxy-carbonyl)-2-piperidinecarboxylic acid methyl ester (2.00 g, 7.21 mmol) in THF (20 ml) at room temperature was treated with water (10 ml). Lithium hydroxide (190 mg, 7.93 mmol) was added and the resulting mixture stirred at room temperature for 3 hr. An additional quantity of lithium hydroxide (40 mg, 1.67 mmol) was added and the resulting mixture was stirred for 2 hr prior to the removal of the organic solvent. The resulting solution was washed with diethyl ether and the remaining aqueous layer was made acidic with 2 N HCl prior to a second extraction step with ethyl acetate. The organic layer was then recovered, dried (Na2SO4), filtered and concentrated to reveal a colorless oil (1.9927 g, 105%) which crystallized upon standing: 1H NMR (400 MHz, CDCl3) δ 1.30-1.88 (5H, m), 2.22-2.41 (1H, m), 3.00-3.21 (1H, m), 4.08-4.25 (1H, m), 4.91-5.30 (3H, m), 7.27-7.48 (5H, m).

1. stirringthe resulting mixture was stirred for 2 hr
2. customto the removal of the organic solvent
3. washThe resulting solution was washed with diethyl ether
4. extractionto a second extraction step with ethyl acetate
5. customThe organic layer was then recovered
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customcrystallized