Reaction #1885044

Reaction equation

(R)-2-(tert-butyldiphenylsilyloxy)-4-hydroxy-N-phenylbutanamide

tert-butyl-N-tert-butoxycarbonyliminocarbamate

→

(R)-3-(tert-butyldiphenylsilyloxy)-1-phenylpyrrolidin-2-one

Yield 99.9%

Solvents

THF

THF

Conditions

Workup

1. 1
   Otherthe cooling bath was removed
2. 2
   TemperatureThe reaction mixture was then cooled to 0° C.
3. 3
   Otherthe cooling bath removed
4. 4
   workup.STIRRINGthe reaction mixture stirred at RT for 45 min
5. 5
   workup.ADDITIONThe reaction mixture was poured into water
6. 6
   Extractionextracted with EtOAc (3×)
7. 7
   WashThe combined organics were washed with water (2×), brine
8. 8
   Dryingdried over MgSO4
9. 9
   Otherevaporated to dryness
10. 10
    OtherPurification by silica gel chromatography (1-10% EtOAc in hexane)

Procedure

To a solution of tert-butyl-N-tert-butoxycarbonyliminocarbamate (2.44 g, 10.61 mmol) in THF (17.25 mL) at 0° C. was added n-tributylphosphine (2.15 g, 2.64 mL, 10.61 mmol) dropwise, the cooling bath was removed and the reaction mixture stirred at RT for 20 min. The reaction mixture was then cooled to 0° C. and a solution of (R)-2-(tert-butyldiphenylsilyloxy)-4-hydroxy-N-phenylbutanamide (1.15 g, 2.65 mmol) in THF (17.25 mL) was added slowly, the cooling bath removed and the reaction mixture stirred at RT for 45 min. The reaction mixture was poured into water and extracted with EtOAc (3×). The combined organics were washed with water (2×), brine, dried over MgSO4 and evaporated to dryness. Purification by silica gel chromatography (1-10% EtOAc in hexane) afforded (R)-3-(tert-butyldiphenylsilyloxy)-1-phenylpyrrolidin-2-one (1.1 g, 96%) as an oil. 1H-NMR (400 MHz, DMSO-d6) δ 7.81 (dd, J=1.5, 7.7 Hz, 2H), 7.72-7.66 (m, 4H), 7.51-7.36 (m, 8H), 7.15 (m, 1H), 4.51 (dd, J=8.1, 9.2 Hz, 1H), 3.72-3.59 (m, 2H), 2.26-2.21 (m, 1H), 2.03-1.98 (m, 1H) and 1.06 (s, 9H) ppm. LC/MS (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA)), m/z: M+1 obs=416.7; tR=2.40 min.

Source