Reaktion #59938

Reaktionsgleichung

2-oxobutyl benzoate

1,3-propanediol

triethyl orthoformate

p-toluenesulfonic acid monohydrate

→

title compound

Ausbeute 66.5%

(2-ethyl-1,3-dioxan-2-yl)methyl benzoate

Ausbeute 66.5%

Lösungsmittel

diethyl ether

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenthe mixture was washed with water
2. 2
   TrocknenThe organic layer was dried over sodium sulfate
3. 3
   Filtrationfiltrated
4. 4
   EinengenThe filtrate was concentrated under reduced pressure
5. 5
   workup.DISSOLUTIONThe residue was dissolved in heptane/ethyl acetate (12/1)
6. 6
   Waschensubjected to NH silica gel column chromatography (elution solvent: n-heptane/ethyl acetate=12/1)

Vorschrift

A mixture of 2-oxobutyl benzoate (5 g, 26 mmol), 1,3-propanediol (5.94 g, 78 mmol), triethyl orthoformate (3.85 g, 26 mmol) and p-toluenesulfonic acid monohydrate (448 mg, 2.36 mmol) was stirred at room temperature for 3 hours and 30 minutes. To the reaction mixture, ethyl acetate and diethyl ether were added and the mixture was washed with water and a saturated saline solution. The organic layer was dried over sodium sulfate and filtrated. The filtrate was concentrated under reduced pressure. The residue was dissolved in heptane/ethyl acetate (12/1) and subjected to NH silica gel column chromatography (elution solvent: n-heptane/ethyl acetate=12/1) to obtain the title compound (4.33 g, 65.5%) as a colorless viscous oil.

Quelle