反应详情

To a stirred mixture of (2S*,3R*)-2-amino-3-hydroxy-pentanoic acid (0.068 g, 0.51 mmol) and NaHCO3 (0.128 g, 1.53 mmol) in H2O (2.0 mL), at rt, the isomeric mixture containing 5-phenyl-pentyl-2-pyridyl-carbonate and 5-phenyl-pentyl-2-oxopyridine-1-carboxylate (0.218 g, 0.77 mmol) [prepared as for example 32, step 1] in THF (2.0 mL) was added. After 15 h at rt, the crude mixture was rotary evaporated to remove the organics and subsequently extracted with Et2O (3×10 mL). The aqueous phase was acidified with 2.0 M HCl solution to pH 2-3 and subsequently extracted with AcOEt (3×20 mL). The organic fraction was dried over Na2SO4, filtered and concentrated to dryness to afford the title compound (0.076 g, 46% over 3 steps), as an off-white solid, which was used in the next step without further purification. MS (ESI) m/z: 324 [M−NH4]+; (ESI) m/z: 322 [M−H]−. 1H NMR (DMSO-d6) δ 0.85 (t, J=7.38 Hz, 3H), 1.28-1.49 (m, 4H), 1.50-1.68 (m, 4H), 2.58 (t, J=7.67 Hz, 2H), 3.79 (td, J=2.93, 6.83 Hz, 1H), 3.97 (t, J=6.60 Hz, 2H), 3.99-4.11 (m, 1H), 6.63 (d, J=9.23 Hz, 1H), 7.12-7.32 (m, 5H).

1. additionwas added
2. customthe crude mixture was rotary evaporated
3. customto remove the organics and
4. extractionsubsequently extracted with Et2O (3×10 mL)
5. extractionsubsequently extracted with AcOEt (3×20 mL)
6. dry with materialThe organic fraction was dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated to dryness