Reaktion #1340593

Reaktionsgleichung

acetic acid

Ketone

(S)-Benzyl (1-(4-((tert-butyloxycarbonylamino)methyl)phenyl)-4-methyl-3-oxopent-4-en-2-yl)carbamate

NaBH4

→

title compound

Benzyl((2S,3R)-1-(4-((tert-butyloxycarbonylamino) methyl)phenyl)-3-hydroxy-4-methylpent-4-en-2-yl)carbamate

Lösungsmittel

MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe mixture was concentrated under reduced pressure
2. 2
   workup.DISSOLUTIONThe resulting residue was dissolved in EtOAc
3. 3
   Extraktionextracted with half saturated aq. NaHCO3 (2×) and brine
4. 4
   Trocknendried over MgSO4
5. 5
   Einengenconcentrated in vacuo

Vorschrift

Ketone 12 (2.81 g, 4.30 mmol) was dissolved in MeOH (25 mL) and cooled to 0° C. To this were added CeCl3.7H2O (1.5 eq., 6.45 mmol, 2.43 g) and NaBH4 (1.4 eq., 6.0 mmol, 227 mg) portion-wise and the mixture was stirred for 5 minutes. after which TLC analysis indicated a complete conversion. Glacial acetic acid (10 mL) was added and the mixture was concentrated under reduced pressure. The resulting residue was dissolved in EtOAc and extracted with half saturated aq. NaHCO3 (2×) and brine, dried over MgSO4 and concentrated in vacuo. The title compound was obtained as a colourless oil (yield: 1.79 g, 3.94 mmol, 92%). 1H NMR (400 MHz, CDCl3): δ=7.31-7.01 (m, 9H), 5.30 (d, J=9.18 Hz, 1H), 5.06 (s, 1H), 5.00 (d, J=5.19 Hz, 1H), 4.96-4.91 (m, 3H), 4.21 (d, J=4.41 Hz, 1H), 4.16-4.11 (m, 1H), 4.07-3.98 (m, 1H), 2.85 (d, J=12.55 Hz, 1H), 2.65 (dd, J=13.60, 10.41 Hz, 1H), 1.77 (s, 3H), 1.44 (s, 9H) ppm. 13C NMR (100 MHz, CDCl3): δ=155.96, 155.85, 144.44, 137.34, 136.44, 129.34, 128.19, 127.77, 127.66, 127.25, 112.17, 79.25, 76.65, 66.27, 54.06, 44.15, 33.69, 28.22, 18.73 ppm. [α]D23=−18.7 (c=1, CHCl3). HRMS: calcd. for C26H34N2O5 455.25405 [M+H]+. Found 455.25392.

Quelle