Reaction #1340593

Reaction equation

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

Solvents

MeOH

Conditions

Workup

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

Procedure

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.

Source