Ethanone, 1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)- → HCID 19002101, compound

HRID 2067176Notes

Reaction equation

HRID 2067176 reaction equation
[CH3:1][C:2]1[C:3]([C:16](=O)[CH3:17])=[CH:4][C:5]2[C:6]([CH3:15])([CH3:14])[CH2:7][CH2:8][C:9]([CH3:13])([CH3:12])[C:10]=2[CH:11]=1.[C:19](O[K])(C)(C)C>C1COCC1>[C:2]([C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:16]=1[CH3:17])[C:9]([CH3:13])([CH3:12])[CH2:8][CH2:7][C:6]2([CH3:15])[CH3:14])([CH3:1])=[CH2:19]

Participants

4

Reactant 2

HCID 87186Ethanone, 1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)-HCID 178418922HCID 178418922, compound

Product 1

HCID 19002101HCID 19002101, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

In a nitrogen-filled glove box, to 250 ml round bottomed flask fitted with a magnetic stirring bar containing 1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-yl)ethanone (0.5 g, 2.05 mmol) and 50 ml of dry THF was added [+PPh3MeI−] (1.24 g, 3.07 mmol), followed by tBuOK (343 g, 3.06 mmol). The mixture was stirred at room temperature. After 24 h, in situ GC/MS analysis showed complete conversion of the carbonyl compound to the alkene product. The mixture was filtered to remove the salt. The solvent was removed in vacuo and the resulting solid was redissolved in hexane and then cooled in the refrigerator for 24 h to crystallise the PPh3O. The mixture was filtered and cooled again to remove additional PPh3O. This step has to be repeated at least 4 times to remove all of the PPh3O. Finally, the solvent was removed in vacuo to obtain the pure alkene. Alternatively, a faster method of purification, after removal of the salt by filtration, involves concentration in vacuo and then Kugelrohr distillation (100-140° C., 3×10−4 torr), which gave an analytically pure sample of 4a (396 mg, 80%); m.p. 39-40° C.

Workup

  1. additionIn a nitrogen-filled glove box
  2. customto 250 ml round bottomed flask fitted with a magnetic stirring bar
  3. additionwas added [+PPh3MeI−] (1.24 g, 3.07 mmol)
  4. filtrationThe mixture was filtered
  5. customto remove the salt
  6. customThe solvent was removed in vacuo
  7. dissolutionthe resulting solid was redissolved in hexane
  8. temperaturecooled in the refrigerator for 24 h
  9. customto crystallise the PPh3O
  10. filtrationThe mixture was filtered
  11. temperaturecooled again
  12. customto remove additional PPh3O
  13. customto remove all of the PPh3O
  14. customFinally, the solvent was removed in vacuo

Sources & evidence

ORD record
ord-cb69cc9027bc4f0790d441b12ba7899b
Source dataset
uspto-grants-2012_10
Patent number
US08293803B2

Reaction notes

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