Pyridine → 6,6-Ethylenedioxy-2-methyl-2-(4'-oxobutyl)-oxepane

HRID 851334Notes

Reaction equation

HRID 851334 reaction equation
[CH2:1]1[CH2:17][O:16][C:3]2([CH2:9][O:8][C:7]([CH2:11][CH2:12][CH2:13][CH2:14][OH:15])([CH3:10])[CH2:6][CH2:5][CH2:4]2)[O:2]1.N1C=CC=CC=1>C(Cl)Cl.N1C=CC=CC=1.[O-2].[O-2].[O-2].[Cr+6].[O-2].[O-2].[O-2].[Cr+6]>[CH2:17]1[CH2:1][O:2][C:3]2([CH2:9][O:8][C:7]([CH3:10])([CH2:11][CH2:12][CH2:13][CH:14]=[O:15])[CH2:6][CH2:5][CH2:4]2)[O:16]1

Participants

6

Reactant 2

HCID 1049PyridineHCID 131881856,6-Ethylenedioxy-2-(4'-hydroxybutyl)-2-methyloxepane

Product 1

HCID 131881866,6-Ethylenedioxy-2-methyl-2-(4'-oxobutyl)-oxepaneYield 70%

Reagents, catalysts & solvents 3

HCID 10219390chromium (VI) trioxideCatalystHCID 131712986HCID 131712986, compoundCatalystHCID 6344DichloromethaneSolvent2×

Procedure

Dry celite (40 g) and 6,6-ethylenedioxy-2-(4'-hydroxybutyl)-2-methyloxepane (4.88 g, 0.0196 mol) in methylene chloride (100 ml) are added to a pyridine-chromium trioxide solution [prepared from pyridine (18.6 g, 0.0284 mol) and chromium trioxide (11.8 g, 0.118 mol)]in dry methylene chloride (500 ml) at 10° C. in a nitrogen atmosphere. After 5 hours the mixture is filtered and the celite is washed with methylene chloride (10×50 ml). The solvent is removed at reduced pressure. The residue is diluted with ether (200 ml), filtered and the ether is removed at reduced pressure. The crude product (4.7 g) is chromatographed on SilicAR CC-7 (100 g) in hexane. Elution with 20% ethyl acetate/hexane gives 6,6-ethylenedioxy-2-methyl-2-(4'-oxobutyl)-oxepane (14) as a clear colorless oil (3,3 g, 70%): ir (neat) 1725 cm-1 (CHO).

Workup

  1. customat 10° C.
  2. filtrationAfter 5 hours the mixture is filtered
  3. washthe celite is washed with methylene chloride (10×50 ml)
  4. customThe solvent is removed at reduced pressure
  5. additionThe residue is diluted with ether (200 ml)
  6. filtrationfiltered
  7. customthe ether is removed at reduced pressure
  8. customThe crude product (4.7 g) is chromatographed on SilicAR CC-7 (100 g) in hexane
  9. washElution with 20% ethyl acetate/hexane

Sources & evidence

ORD record
ord-d730858822414805b23109e52e64a5a3
Source dataset
uspto-grants-1983_05
Patent number
US04384126

Reaction notes

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