1-(Triphenylphosphoranylidene)acetone → 1-(N-Cbz-2-pyrrolidinyl)-1-buten-3-one

HRID 744955Notes

Reaction equation

HRID 744955 reaction equation
[C:1]([N:11]1[CH2:17][CH2:16][CH2:15][C@H:12]1[CH:13]=O)([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].C1(P(C2C=CC=CC=2)(C2C=CC=CC=2)=[CH:25][C:26](=[O:28])[CH3:27])C=CC=CC=1>C1C=CC=CC=1>[C:1]([N:11]1[CH2:17][CH2:16][CH2:15][CH:12]1[CH:13]=[CH:25][C:26](=[O:28])[CH3:27])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2]

Participants

4

Reactant 2

HCID 150381-(Triphenylphosphoranylidene)acetoneHCID 11746545(S)-2-Formyl-pyrrolidine-1-carboxylic acid benzyl ester

Product 1

HCID 572702461-(N-Cbz-2-pyrrolidinyl)-1-buten-3-oneYield 69%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a stirred solution of N-Cbz-L-prolinal (6.3 g, 27 mmol, from step 24d above) in 30 mL of benzene was added 9.42 g (29.6 mmol) of 1-triphenylphosphoranylidene-2-propanone (Aldrich) at room temperature. The reaction mixture was heated to reflux for 4 hr. The benzene was removed under vacuum, and the residue was dissolved in ether and cooled for 16 hr. The phosphine oxide by product was removed by filtration, and the solution was further purified by column chromatography on silica gel, eluting with 20% ethyl acetate in hexanes, to afford 4.4 g of the title product (69% yield).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 4 hr
  3. customThe benzene was removed under vacuum
  4. dissolutionthe residue was dissolved in ether
  5. temperaturecooled for 16 hr
  6. customThe phosphine oxide by product was removed by filtration
  7. customthe solution was further purified by column chromatography on silica gel
  8. washeluting with 20% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-d65c60211113446ca4f55d35d801aa7a
Source dataset
uspto-grants-1996_09
Patent number
US05559242

Reaction notes

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