tert-butyl N-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamate → tert-butyl-[(2S,3Z)-1,5-diphenylpent-3-en-2-yl]carbamate

HRID 573009Notes

Reaction equation

HRID 573009 reaction equation
C([Li])CCC.[Br-].C1([P+](C2C=CC=CC=2)(C2C=CC=CC=2)[CH2:14][CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)C=CC=CC=1.[C:34]([O:38][C:39](=[O:51])[NH:40][C@@H:41]([CH2:44][C:45]1[CH:50]=[CH:49][CH:48]=[CH:47][CH:46]=1)[CH:42]=O)([CH3:37])([CH3:36])[CH3:35]>CCCCCC.C1COCC1>[C:34]([O:38][C:39](=[O:51])[NH:40][C@H:41](/[CH:42]=[CH:14]\[CH2:15][C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1)[CH2:44][C:45]1[CH:46]=[CH:47][CH:48]=[CH:49][CH:50]=1)([CH3:37])([CH3:35])[CH3:36]

Participants

6

Reactant 3

HCID 6998013tert-butyl N-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamateHCID 10863251Phenethyltriphenylphosphonium bromideHCID 178418339Butyllithium

Product 1

HCID 131732830tert-butyl-[(2S,3Z)-1,5-diphenylpent-3-en-2-yl]carbamate

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
0 °C

Procedure

Under argon, 842 μL (2.1 mmol) 2.5 M n-butyllithium solution in hexane was added to a suspension of 986 mg (2.2 mmol) triphenyl-(2-phenylethyl)phosphonium bromide [can be synthesized, e.g., according to R. W. Hartmann, M. Reichert, Archiv der Pharmazie 333, 145 (2000); K. C. Nicolaou et al., European J. Chem. 1, 467 (1995)] in 125 mL THF at −78° C., and the mixture was then stirred for one hour at 0° C. The reaction mixture was then cooled back to −78° C. and a solution of 500 mg (2.0 mmol) tert-butyl-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamate in 5 mL dry THF was added. The batch was heated to 0° C. and stirred further for three hours at this temperature. The reaction was then terminated by adding saturated aqueous ammonium chloride solution. The mixture was diluted with MTBE, the phases were separated, and the organic phase was dried over magnesium sulfate and concentrated in vacuo. The residue was purified over a silica gel column using cyclohexane/ethyl acetate 5:1 as the mobile phase. After concentrating the corresponding fractions, 173 mg (25.6% of the theoretical) of the Boc-protected intermediate, tert-butyl-[(2S,3Z)-1,5-diphenylpent-3-en-2-yl]carbamate was obtained.

Workup

  1. temperatureThe reaction mixture was then cooled back to −78° C.
  2. temperatureThe batch was heated to 0° C.
  3. stirringstirred further for three hours at this temperature
  4. customThe reaction was then terminated
  5. additionby adding saturated aqueous ammonium chloride solution
  6. additionThe mixture was diluted with MTBE
  7. customthe phases were separated
  8. dry with materialthe organic phase was dried over magnesium sulfate
  9. concentrationconcentrated in vacuo
  10. customThe residue was purified over a silica gel column
  11. concentrationAfter concentrating the corresponding fractions, 173 mg (25.6% of the theoretical) of the Boc-

Sources & evidence

ORD record
ord-ef778fdf66234a938fc7a77d2a57027f
Source dataset
uspto-grants-2015_05
Patent number
US09029406B2

Reaction notes

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