Diethyl Ether → t-Butyldimethylsilyloxybicyclo[2,2,1]heptan-2-one

HRID 2163484Notes

Reaction equation

HRID 2163484 reaction equation
[Si:1]([O:8][CH:9]([CH2:13][CH2:14][CH2:15][CH2:16][CH3:17])[CH:10]=CI)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C([Li])CCC.[Cl-].[NH4+].CC[O:27]CC>CCCCCC.CN(P(N(C)C)N(C)C)C>[Si:1]([O:8][C:9]12[CH2:10][CH:15]([CH2:14][CH2:13]1)[CH2:16][C:17]2=[O:27])([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:2])[CH3:3]

Participants

7

Reactant 4

HCID 3283Diethyl Ether2×HCID 25517Ammonium ChlorideHCID 534008573-t-Butyldimethylsilyloxy-1-iodo-1-octeneHCID 178418339Butyllithium

Product 1

HCID 22752025t-Butyldimethylsilyloxybicyclo[2,2,1]heptan-2-one

Reagents, catalysts & solvents 2

HCID 8058HexaneSolventHCID 15355Hexamethylphosphorous triamideSolvent

Procedure

3-t-Butyldimethylsilyloxy-1-iodo-1-octene (6.07 g) in dry light petroleum (b.p. 60°-80°, 50 ml) was cooled, under nitrogen, to -70°, 2.1 M n-butyllithium in hexane solution (8.0 ml) was added and the solution was stirred 1/2 hour at -70°. A solution of cuprous n-propyl acetylide (2.15 g) in ether (25 ml) and hexamethylphosphorus triamide (6.04 ml) was added to this solution which was stirred for a further 15 minutes at -70°. 3-endo-t-Butyldimethylsilyloxytricyclo[3,2,0,02,7 ]heptan-6-one (3.7 g) in dry ether (ca. 50 ml) was then added to the orange solution which was stored at -70° for 11/2 hours, and warmed to -30°. The cold reaction mixture was poured into saturated ammonium chloride solution (40 ml) and shaken. The organic layer was removed and the aqueous layer was extracted once with ether (20 ml). The combined organic solutions were then shaken with ice-cold 2% sulphuric acid (ca. 200 ml) and the mixture filtered through hyflo to remove precipitated copper salts. The organic layer was removed, washed once with 8% sodium bicarbonate solution and dried (MgSO4). Evaporation of the solvent gave an oil which was chromatographed on silica in light petroleum containing increasing amounts of ethyl acetate. Light petroleum eluted unreacted octene side chain and impure product was eluted with ethyl acetate/ light petroleum (5:95) as a pale yellow oil (5.26 g). Short path distillation afforded pure title compound as a pale yellow oil (3.29 g) b.p. ca. 180°-200°/0.15 mm.

Workup

  1. stirringwas stirred for a further 15 minutes at -70°
  2. customwas stored at -70° for 11
  3. custom2 hours
  4. temperaturewarmed to -30°
  5. customThe cold reaction mixture
  6. stirringshaken
  7. customThe organic layer was removed
  8. extractionthe aqueous layer was extracted once with ether (20 ml)
  9. stirringThe combined organic solutions were then shaken with ice-cold 2% sulphuric acid (ca. 200 ml)
  10. filtrationthe mixture filtered through hyflo
  11. customto remove
  12. customprecipitated copper salts
  13. customThe organic layer was removed
  14. washwashed once with 8% sodium bicarbonate solution
  15. dry with materialdried (MgSO4)
  16. customEvaporation of the solvent
  17. customgave an oil which
  18. customwas chromatographed on silica in light petroleum containing
  19. temperatureincreasing amounts of ethyl acetate
  20. washLight petroleum eluted unreacted octene side chain and impure product was eluted with ethyl acetate/ light petroleum (5:95) as a pale yellow oil (5.26 g)
  21. distillationShort path distillation

Sources & evidence

ORD record
ord-a57898efe1054ed59c5ea276653dd7c6
Source dataset
uspto-grants-1979_01
Patent number
US04134911

Reaction notes

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