Ammonium Chloride → (2S,3S)-(-)-3-tert-Butoxycarbonylamino-1,2-epoxy-4-phenylbutane

To a magnetically stirred solution of 2(S)-t-butyldimetylsilyloxy-3(R)-(t-butyloxycarbonyl)amino-1-chloro-4-phenylbutane (30.0 mg, 0.073 mmol) in THF (0.5 mL) was added a 1 M solution of TBAF in THF (0.11 mL, 0.109 mmol) at 0° C. After 10 min, stirring was continued at room temperature for 40 min. The reaction mixture was treated with sat NH4Cl (0.5 mL), diluted with water (2 mL), and extracted with EtOAc (3 mL×3). The combined organic layers were washed with brine (3 mL), dried over anhyd magnesium sulfate, filtered, and concentrated. The residue was dissolved with MeOH (0.5 mL) and treated with KOH at 0° C. Stirring was continued at room temperature for 2 h. Solvent was removed under reduced pressure, diluted with water (2 mL), and extracted with EtOAc (3 mL×3). The combined organic layers were washed with brine (3 mL), dried over anhydrous magnesium sulfate, filtered, concentrated and column-chromatographed (10% EtOAc in n-Hex) to provide 3(S)-(t-butyloxycarbonyl)amino-1,2(S)-epoxy-4-phenylbutane (14.4 mg) as a white solid.

1. waitwas continued at room temperature for 40 min
2. extractionextracted with EtOAc (3 mL×3)
3. washThe combined organic layers were washed with brine (3 mL)
4. dry with materialdried over anhyd magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. dissolutionThe residue was dissolved with MeOH (0.5 mL)
8. additiontreated with KOH at 0° C
9. stirringStirring
10. waitwas continued at room temperature for 2 h
11. customSolvent was removed under reduced pressure
12. additiondiluted with water (2 mL)
13. extractionextracted with EtOAc (3 mL×3)
14. washThe combined organic layers were washed with brine (3 mL)
15. dry with materialdried over anhydrous magnesium sulfate
16. filtrationfiltered
17. concentrationconcentrated
18. customcolumn-chromatographed (10% EtOAc in n-Hex)

ORD-Eintrag

ord-4ba7670ab1e74f8b863db3a2036d9db2

Quelldatensatz

uspto-grants-2003_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06573388B1