Sodium hydride → 4-(3,5-Dibenzyloxyphenyl)-1-phenoxypent-3-ene

HRID 1995705Notes

Reaction equation

HRID 1995705 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:7]=[C:6]([O:18][CH2:19][C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[CH:5]=1)=O.[Br-].[O:27]([CH2:34][CH2:35][CH2:36][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1.[H-].[Na+]>O1CCCC1.CS(C)=O>[CH2:19]([O:18][C:6]1[CH:5]=[C:4]([C:2]([CH3:1])=[CH:36][CH2:35][CH2:34][O:27][C:28]2[CH:29]=[CH:30][CH:31]=[CH:32][CH:33]=2)[CH:9]=[C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:7]=1)[C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=1

Participants

6

Reactant 3

HCID 24758Sodium hydrideHCID 120098Ethanone, 1-(3,5-bis(phenylmethoxy)phenyl)-HCID 3048782(3-Phenoxypropyl)(triphenyl)phosphanium bromide

Product 1

HCID 544983714-(3,5-Dibenzyloxyphenyl)-1-phenoxypent-3-eneYield 75%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 8028TetrahydrofuranSolvent

Procedure

Under a nitrogen atmosphere a mixture of 3,5-dibenzyloxyacetophenone (50.0 g., 0.15M) in tetrahydrofuran (175 ml.) and 3-phenoxypropyltriphenylphosphonium bromide (7.18 g., 0.15M) in dimethylsulfoxide (450 ml.) is added dropwise over 1.75 hours to a suspension of 50% sodium hydride (7.89 g., 0.165M) (previously washed with pentane) in tetrahydrofuran (75 ml.) maintained at 0°-5° C. After stirring for 4 hours at 0°-5° C. the reaction is allowed to warm to room tempertaure and is then carefully stirred into ice water (2000 ml.), acidified with concentrated hydrochloric acid, and extracted with ethyl acetate (5×400 ml.). The combined organic phases are washed with saturated sodium chloride solution (3×300 ml.), dried over sodium sulfate and concentrated under vacuum to yield an oil which is triturated with ether to precipitate triphenylphosphine oxide. Filtration, followed by concentration of the filtrate, gives an oily residue which is chromatographed over silica gel (1300 g.) eluting with benzene-hexane consisting of 30% to 100% benzene. From the middle fractions 51 g. (75%) of 4-(3,5-dibenzyloxyphenyl)-1-phenoxypent-3-ene is isolated as an oil; Rf =0.8 (silica gel, 2-benzene:1-hexane); m/e-450 (m+).

Workup

  1. washpreviously washed with pentane) in tetrahydrofuran (75 ml.)
  2. temperaturemaintained at 0°-5° C
  3. temperatureto warm to room tempertaure
  4. stirringis then carefully stirred into ice water (2000 ml.)
  5. extractionextracted with ethyl acetate (5×400 ml.)
  6. washThe combined organic phases are washed with saturated sodium chloride solution (3×300 ml.)
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated under vacuum
  9. customto yield an oil which
  10. customis triturated with ether
  11. customto precipitate triphenylphosphine oxide
  12. filtrationFiltration
  13. customgives an oily residue which
  14. customis chromatographed over silica gel (1300 g.)
  15. washeluting with benzene-hexane

Sources & evidence

ORD record
ord-a27054b1093141dc9b074acc10db75d5
Source dataset
uspto-grants-1983_09
Patent number
US04405626

Reaction notes

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