Reaktion #318447

Reaktionsgleichung

2-[(12-bromododecyl)oxy]tetrahydro-2H-pyran

cyclohexylmagnesium bromide

sulfuric acid

→

[(12-cyclohexyldodecyl)oxy]-tetrahydro-2H-pyran

Lösungsmittel

THF

tetrahydrofuran

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile maintaining the reaction temperature at 10°-15° C
2. 2
   workup.STIRRINGThereafter, the reaction mixture is stirred for 7 hours at room temperature
3. 3
   Sonstigethe reaction
4. 4
   SonstigeThe undissolved substances are removed by filtration
5. 5
   Waschenthe precipitates are washed with ethyl acetate
6. 6
   Waschenthe resulting solution is washed with water
7. 7
   Trocknenan aqueous sodium bicarbonate solution and then water and is dried
8. 8
   SonstigeThe solvent is removed by distillation under reduced pressure

Vorschrift

Into 250 ml of tetrahydrofuran (THF) is dissolved 57.8 g of 2-[(12-bromododecyl)oxy]tetrahydro-2H-pyran, to which a solution of 0.35 g of dilithium tetrachlorocuprate in 16 ml of THF is added dropwise at room temperature with stirring under nitrogen streams. To the resulting solution, a solution of 39.6 g of cyclohexylmagnesium bromide in 200 ml of THF is added dropwise while maintaining the reaction temperature at 10°-15° C. Thereafter, the reaction mixture is stirred for 7 hours at room temperature to complete the reaction. The reaction mixture is then acidified with 2N sulfuric acid under ice cooling. The undissolved substances are removed by filtration and the precipitates are washed with ethyl acetate. The THF layer and the ethyl acetate layer are combined and the resulting solution is washed with water, an aqueous sodium bicarbonate solution and then water and is dried. The solvent is removed by distillation under reduced pressure to leave crude [(12-cyclohexyldodecyl)oxy]-tetrahydro-2H-pyran which in turn is dissolved in 450 ml of methanol. Amberlyst® H-15 (4.5 g) is added to the methanol solution and the mixture is stirred at 45° C. for 2 hours. The resin is then filtered off and the filtrate is concentrated to leave a residue. Purification of the residue by silica gel column chromatography yields 20.6 g of the captioned compound as colorless solids.

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