Reaktion #6153

Reaktionsgleichung

2-hexyl-3-hydroxy-(R)-5-[(tetrahydro-2H-pyran-2-yl)oxy]hexadecanoic acid

toluene-4-sulfonic acid monohydrate

→

tetrahydro-3-hydroxy-(R)-6-undecyl-2H-pyran-2-one

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was heated to 55°-60° C. until the reaction
2. 2
   SonstigeThe solvent was removed in vacuo
3. 3
   workup.DISSOLUTIONthe residue was dissolved in 160 ml of dichloromethane
4. 4
   SonstigeThe reaction mixture was evaporated
5. 5
   SonstigeThe material obtained
6. 6
   Sonstigewas chromatographed on silica gel

Vorschrift

M)a) 15.4 g of a diastereomer mixture of 2-hexyl-3-hydroxy-(R)-5-[(tetrahydro-2H-pyran-2-yl)oxy]hexadecanoic acid were dissolved in 160 ml of ethanol and 800 mg of toluene-4-sulfonic acid monohydrate were added. The reaction mixture was heated to 55°-60° C. until the reaction was finished. The solvent was removed in vacuo and the residue was dissolved in 160 ml of dichloromethane. The solution was stirred at room temperature for 1 hour. The reaction mixture was evaporated. The material obtained was chromatographed on silica gel. There was obtained tetrahydro-3-hydroxy-(R)-6-undecyl-2H-pyran-2-one, m.p. 95°-96° C.

Quelle