反应详情

To a stirred mixture of (2S*,3R*)-2-amino-3-hydroxy-4,4-dimethyl-pentanoic acid (0.353 g, 2.19 mmol) and NaHCO3 (0.184 g, 0.84 mmol) in H2O (15 mL), at rt, the isomeric mixture containing (4-phenylphenyl)-methyl-2-pyridyl carbonate and (4-phenylphenyl)-methyl-2-oxopyridine-1-carboxylate (0.815 g, 2.2 mmol) [prepared as for example 17, step 1] in THF (15 mL) was added. After 15 h at rt, the crude mixture was rotary evaporated to remove the organics and subsequently extracted with Et2O (3×20 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 (0.181 g, 21%), which was used in the next step without further purification. MS (ESI) m/z: 410 [M−K]+; (ESI) m/z: 370 [M−H]−.

1. additionwas added
2. customthe crude mixture was rotary evaporated
3. customto remove the organics and
4. extractionsubsequently extracted with Et2O (3×20 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