Ethylene Glycol → 2-(4'-Benzyloxybutyl)-6,6-ethylenedioxy-2-methyloxepane

HRID 851332Notes

Reaction equation

HRID 851332 reaction equation
C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH2:12]([O:19][CH2:20][CH2:21][CH2:22][CH2:23][C:24]1([CH3:32])[CH2:30][CH2:29][CH2:28][C:27](=[O:31])[CH2:26][O:25]1)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[CH2:33](O)[CH2:34][OH:35].C([O-])(O)=O.[Na+]>C1C=CC=CC=1>[CH2:12]([O:19][CH2:20][CH2:21][CH2:22][CH2:23][C:24]1([CH3:32])[CH2:30][CH2:29][CH2:28][C:27]2([O:35][CH2:34][CH2:33][O:31]2)[CH2:26][O:25]1)[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1

Participants

6

Reactant 4

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 516892Sodium BicarbonateHCID 131881832-(4'-Benzyloxybutyl)-2-methyl-oxepan-6-one

Product 1

HCID 131881842-(4'-Benzyloxybutyl)-6,6-ethylenedioxy-2-methyloxepaneYield 99%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

p-Toluenesulfonic acid (200 mg) is added to a solution of 2-(4'-benzyloxybutyl)-2-methyl-oxepan-6-one (5.9 g, 0.021 mol), ethylene glycol (30 ml) and dry benzene (200 ml) and the mixture is refluxed for 17 hours in a nitrogen atmosphere with a Dean-Stark apparatus. The solution is cooled and poured into a satd. NaHCO3 solution. The benzene layer is separated and the aqueous phase is extracted with ether (3×50 ml). The organic layers are combined, dried (MgSO4) and the solvents removed at reduced pressure. The crude product is chromatographed on SilicAR CC-7 (125 g) in hexane. Elution with 10% ethyl acetate/hexane gives 2-(4'-benzyloxybutyl)-6,6-ethylenedioxy-2-methyloxepane as a clear colorless oil (6.7 g, 99%): nmr (CDCl3) δ1.10 (s., 3H, CH3), 3.5 (m, 4H, O--CH2 --and O--CH2 --CH2), 3.96 (s, 4H, ketal) 4.48 (s, 2H, O--CH2 --Ph), 730 (s, 5H, aromatic).

Workup

  1. temperaturethe mixture is refluxed for 17 hours in a nitrogen atmosphere with a Dean-Stark apparatus
  2. temperatureThe solution is cooled
  3. additionpoured into a satd
  4. customThe benzene layer is separated
  5. extractionthe aqueous phase is extracted with ether (3×50 ml)
  6. dry with materialdried (MgSO4)
  7. customthe solvents removed at reduced pressure
  8. customThe crude product is chromatographed on SilicAR CC-7 (125 g) in hexane
  9. washElution with 10% ethyl acetate/hexane

Sources & evidence

ORD record
ord-7cd2bb068ce649d0a97f617100667652
Source dataset
uspto-grants-1983_05
Patent number
US04384126

Reaction notes

Loading…