Toluene → 2-Tert.-butyl-4,4,7,7,-tetramethyl-1,3-dioxacycloheptane

HRID 247357

Reaction equation

HRID 247357 reaction equation
[CH3:1][C:2]([OH:10])([CH2:4][CH2:5][C:6]([CH3:9])([OH:8])[CH3:7])[CH3:3].[CH:11](=O)[C:12]([CH3:15])([CH3:14])[CH3:13].C1(C)C=CC=CC=1>C1(C)C=CC(S(O)(=O)=O)=CC=1.O>[C:12]([CH:15]1[O:10][C:2]([CH3:3])([CH3:1])[CH2:4][CH2:5][C:6]([CH3:9])([CH3:7])[O:8]1)([CH3:14])([CH3:13])[CH3:11]

Participants

6

Reactant 3

HCID 1140TolueneHCID 80312,5-Dimethyl-2,5-hexanediolHCID 12417Pivalaldehyde

Product 1

HCID 139807482-Tert.-butyl-4,4,7,7,-tetramethyl-1,3-dioxacycloheptaneYield 85%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 962WaterSolvent

Procedure

A mixture of 730 g (5 mol) of 2,5-dimethylhexane-2,5-diol, 3 g of p-toluenesulfonic acid, 430 g (5 mol) of pivalaldehyde and 1 l of toluene was refluxed for 4 hours (h) during which the water of reaction produced (90 ml) was removed. The reaction mixture was then cooled down to room temperature (RT) and stirred up with 10 ml of 25% strength aqueous sodium hydroxide solution, the phases were separated, the organic phase was washed with a little water until neutral, and the toluene was then removed at 50°-60° C. The residue obtained was fractionated under reduced pressure affording 909 g (4.25 mol) of 2-tert.-butyl-4,4,7,7,-tetramethyl-1,3-dioxacycloheptane (boiling point 54° C./0.2 mbar). This corresponds to a yield of 85% of theory.

Workup

  1. temperaturewas refluxed for 4 hours (h) during which
  2. customproduced (90 ml)
  3. customwas removed
  4. customthe phases were separated
  5. washthe organic phase was washed with a little water until neutral, and the toluene
  6. customwas then removed at 50°-60° C
  7. customThe residue obtained

Sources & evidence

ORD record
ord-03ed008d92b34129a4600f2fd633702e
Source dataset
uspto-grants-1987_11
Patent number
US04707302

Linked notes

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