Tetrahydrofuran → 2,6-Dimethyl-5-methylene-1-hepten-4-ol

HRID 638115Notes

Reaction equation

HRID 638115 reaction equation
[Mg].O1CCCC1.Cl[CH2:8][C:9]([CH3:11])=[CH2:10].[CH:12]([C:15](=[CH2:18])[CH:16]=[O:17])([CH3:14])[CH3:13]>C1(C)C=CC=CC=1>[CH3:11][C:9]([CH2:8][CH:16]([OH:17])[C:15](=[CH2:18])[CH:12]([CH3:14])[CH3:13])=[CH2:10]

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 112413-Chloro-2-methyl-1-propeneHCID 781313-Methyl-2-methylenebutyraldehydeHCID 5462224Magnesium

Product 1

HCID 202373802,6-Dimethyl-5-methylene-1-hepten-4-olYield 73.8%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of magnesium turnings (146 grams) and tetrahydrofuran (2,000 grams) is heated to reflux with vigorous agitation. To this mixture is added a mixture of 3-chloro-2-methylpropene (500 grams), toluene (75 grams), and 3-methyl-2-methylenebutanal (500 grams prepared according to Example I), at such a rate as to maintain reflux. The addition requires approximately four hours. The mass is stirred at reflux for 30 minutes and is then cooled to room temperature and quenched into excess ice cold 10% aqueous acetic acid mixture. The organic layer is washed successively with an equal volume of water, saturated sodium carbonate solution and saturated salt solution. Rapid distillation at 3-12 mm/Hg pressure using a short column followed by careful redistillation (after bulking) through a 12"×1" Goodloe packed column yields 580 grams of 2,6-dimethyl-5-methylene-1-hepten-4-ol, boiling point range 73°-78° C. at 9 mm/Hg pressure.

Workup

  1. temperatureis heated
  2. temperatureto reflux with vigorous agitation
  3. additionTo this mixture is added
  4. temperatureat such a rate as to maintain
  5. temperaturereflux
  6. additionThe addition
  7. temperatureat reflux for 30 minutes
  8. customquenched into excess ice cold 10% aqueous acetic acid mixture
  9. washThe organic layer is washed successively with an equal volume of water, saturated sodium carbonate solution and saturated salt solution
  10. distillationRapid distillation at 3-12 mm/Hg pressure
  11. distillationfollowed by careful redistillation (after bulking) through a 12"×1"

Sources & evidence

ORD record
ord-6e0361a8166242f1a6b4ca84638e9a0e
Source dataset
uspto-grants-1985_12
Patent number
US04560499

Reaction notes

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