Benzyl Alcohol → Benzyl hydrogen 3,3-dimethylglutarate

HRID 279914

Reaktionsgleichung

Reaktionsgleichung von HRID 279914
[CH3:1][C:2]1([CH3:10])[CH2:8][C:7](=[O:9])[O:6][C:4](=[O:5])[CH2:3]1.[CH2:11]([OH:18])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>>[CH3:1][C:2]([CH3:10])([CH2:3][C:4]([OH:6])=[O:5])[CH2:8][C:7]([O:18][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:9]

Komponenten

3

Edukt 2

HCID 244Benzyl AlcoholHCID 778133,3-Dimethylglutaric anhydride

Produkt 1

HCID 23322892Benzyl hydrogen 3,3-dimethylglutarate

Versuchsvorschrift

3,3-Dimethylglutaric anhydride (5.0 g.) and benzyl alcohol (11 ml.) were heated together at 150° C. for 16 hours. The cooled reaction mixture was partitioned between saturated sodium carbonate solution (50 ml.) and ether (50 ml.). The aqueous layer was separated, acidified with 2M hydrochloric acid and extracted with ether. The extracts were evaporated. The residual yellow oil (4.6 g.) was purified by chromatography on silica gel with methylene chloride as eluant to give benzyl hydrogen 3,3-dimethylglutarate as an oil (1.5 g.); NMR (CDCl3): 1.1 (6H,s, CH3), 2.45+2.47 (4H, 2s, COCH2), 5.12 (2H,s, OCH2), 7.37 (5H, s, aromatic H), 8.45 (1H, br.s, CO2H)ppm. This benzyl ester (1.5 g.) was dissolved in methylene chloride (15 ml.) and stirred with thionyl chloride (2.2 ml.) and N,N-dimethylformamide (DMF) (0.3 ml.) for 3 hours. The solvent was evaporated and the residue was dissolved in dry toluene (15 ml.) and the solution re-evaporated. This was repeated twice to remove excess thionyl chloride. The residual oil (1.5 g.) containing crude benzyl 4-chloroformyl-3,3-dimethylbutyrate was dissolved in methylene chloride (25 ml.). The solution was added to a cooled solution of 1,3-dipalmitin (1.4 g.) in methylene chloride (25 ml.) containing pyridine (0.32 ml.). The mixture was stirred for 2 hours at 0°-5° C. and then for 46 hours at ambient temperature. The solvent was evaporated and the residue was partitioned between ether (70 ml.) and water (3×25 ml.). The organic phase was washed with 2M hydrochloric acid, saturated sodium hydrogen carbonate solution (2×25 ml.) and finally with water (2×25 ml.), and then dried (MgSO4) and evaporated. The residual oil crystallised on treatment with ethanol to give 2-hexadecanoyloxy-1-(hexadecanoyloxymethyl)ethyl 4-benzyloxycarbonyl-3,3-dimethylbutyrate as a white solid (2.5 g.).

Aufarbeitung

  1. customThe cooled reaction mixture
  2. customwas partitioned between saturated sodium carbonate solution (50 ml.) and ether (50 ml.)
  3. customThe aqueous layer was separated
  4. extractionextracted with ether
  5. customThe extracts were evaporated
  6. customThe residual yellow oil (4.6 g.) was purified by chromatography on silica gel with methylene chloride as eluant

Quellen und Nachweise

ORD-Eintrag
ord-c489c34708c84ff5bd36f2c0eab63417
Quelldatensatz
uspto-grants-1986_05
Patentnummer
US04587262

Verknüpfte Notizen

Wird geladen…