Hydrochloric Acid → 3-Nonen-5-ol, 4,8-dimethyl-

HRID 1709142Notes

Reaction equation

HRID 1709142 reaction equation
[Mg].C(Br)CC(C)C.CCCCCBr.C[O:15][CH:16]([C:22]([CH3:26])=[CH:23][CH2:24][CH3:25])[CH2:17][CH2:18][CH:19]([CH3:21])[CH3:20].CC(=CCC)C=O.Cl>CCOCC>[CH3:20][CH:19]([CH2:18][CH2:17][CH:16]([OH:15])[C:22]([CH3:26])=[CH:23][CH2:24][CH3:25])[CH3:21]

Participants

8

Reactant 6

HCID 313Hydrochloric AcidHCID 78911-Bromo-3-methylbutaneHCID 80571-BromopentaneHCID 121772-Methyl-2-pentenalHCID 5462224MagnesiumHCID 54039577HCID 54039577, compound

Product 1

HCID 543168773-Nonen-5-ol, 4,8-dimethyl-

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent3×

Conditions

Temperature
10 °C

Procedure

69.5 g (2.9 g-atoms) of magnesium are placed in 500 ml of absolute ether Subsequently, a solution of 438 g of isoamyl bromide, which contains about 1.5% of n-amyl bromide in accordance with gas chromatography, in 1.2 1 of absolute ether is added dropwise so that the exothermic reaction keeps the ether constantly at the boiling point After completion of the addition, the mixture is held at reflux temperature for a further 30 minutes. The Grignard solution is then cooled to 10° C. 236.5 g (2.41.mol) of 2-methyl 2-pentenal in 600 ml of absolute ether are then added dropwise within 40 minutes, the temperature then lying permanently between 10° C. and 20° C. In order to complete the reaction, the mixture is held at reflux temperature for a further 1 hour. The mixture is subsequently added to ice, decomposed with aqueous hydrochloric acid, the ethereal solution is washed neutral with soda and saturated sodium chloride solution and thereupon dried. The crude product (480 g) remaining behind after distillation of the solvent is fractionally distilled over a Widmer column and gives 312 g of 2,6-dimethyl-6-nonen-5-ol (III) of boiling point 62° C./0.05 Torr, nD25 =1.4479, which contains 1.5% of 4-methyl-3-decen-5-ol in accordance with gas chromatography (Carbowax, 130° C.).

Workup

  1. additionAfter completion of the addition
  2. temperatureat reflux temperature for a further 30 minutes
  3. customthen lying permanently between 10° C. and 20° C
  4. customthe reaction
  5. temperatureat reflux temperature for a further 1 hour
  6. additionThe mixture is subsequently added to ice
  7. washthe ethereal solution is washed neutral with soda and saturated sodium chloride solution
  8. customdried
  9. distillationafter distillation of the solvent
  10. distillationis fractionally distilled over a Widmer column

Sources & evidence

ORD record
ord-849942d04b994aa1adbd68288bd3b9af
Source dataset
uspto-grants-1990_08
Patent number
US04948781

Reaction notes

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