Reacción #696730

Ecuación de reacción

3-(S)-[(benzyloxycarbonyl)amino]-2-(R,S)-hydroxy-4-methylpentanoic acid

pyridine

acetic anhydride

→

3-(S)-[(benzyloxycarbonyl)amino]-2-(R,S)-acetoxy-4-methyl pentanoic acid

Rendimiento 80.0%

Disolventes

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Lavadowashed with water (2×)
2. 2
   SecadoThe organic layer was dried over magnesium sulfate
3. 3
   Filtraciónfiltered
4. 4
   Otroevaporated in vacuo
5. 5
   Otroto give a thick oil
6. 6
   OtroThe residue was purified by column chromatography on silica gel with 15% methanol/dichloromethane

Procedimiento

To a solution of 3-(S)-[(benzyloxycarbonyl)amino]-2-(R,S)-hydroxy-4-methylpentanoic acid (1.70 g, 6.04 mmol) and pyridine (4.9 mL) was added acetic anhydride (5.7 mL, 6.17 g, 60.4 mmol) dropwise at room temperature. The reaction was allowed to stir overnight and was diluted with ethyl acetate and washed with water (2×). The organic layer was dried over magnesium sulfate, filtered and evaporated in vacuo to give a thick oil. The residue was purified by column chromatography on silica gel with 15% methanol/dichloromethane to afford 1.56 g (80%) of 3-(S)-[(benzyloxycarbonyl)amino]-2-(R,S)-acetoxy-4-methyl pentanoic acid as a light yellow viscous oil. FAB MS [M+H] m/z; Calcd: 324, Found: 324.

Fuente