反応 #308371

反応方程式

acetic acid

oxo-ester

(R)-Ethyl-4-[(tert-butoxycarbonyl)amino]tetrahydro-3-oxo-2-thiophenecarboxylate

NaBH4

acetone

→

(R)-ethyl-4-[(tert-butoxycarbonyl)amino]tetrahydro-3-hydroxy-2-thiophenecarboxylate

収率 99.6%

溶媒

EtOH

反応条件

後処理

1. 1
   workup.ADDITIONadded portion wise at −30° C
2. 2
   workup.ADDITIONwere added
3. 3
   濃縮The crude mixture was concentrated at 40° C. under 100 mbar
4. 4
   抽出extracted with EtOAc and brine to pH 7
5. 5
   その他The solvent was removed under 0.1 mbar

実験手順

reduction: The oxo-ester (13) (9.16 g, 31.7 mmole) in EtOH 90 mL was reduced with NaBH4 (844 mg, 22 mmole) added portion wise at −30° C. After 30 min at −30° C., acetone 8.7 mL followed with acetic acid 1.1 mL were added. The crude mixture was concentrated at 40° C. under 100 mbar, extracted with EtOAc and brine to pH 7. The solvent was removed under 0.1 mbar, crude 9.20 g (yield 99%) of (R)-ethyl-4-[(tert-butoxycarbonyl)amino]tetrahydro-3-hydroxy-2-thiophenecarboxylate.

出典