Ethylene Glycol → Methyl 1,4-dioxaspiro[4.5]decane-7-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution composed of 30 g (192 mmol) of crude methyl 3-oxocyclohexanecarboxylate and 430 cm3 of toluene is introduced into a one-liter three-necked flask equipped with a Dean and Stark apparatus, and 14.3 g (230 mmol) of ethylene glycol are then added with 814 mg (4.3 mmol) of para-toluenesulfonic acid monohydrate. The mixture is heated to reflux, the toluene-water azeotrope forms instantaneously and, after 40 min, no further refluxing of azeotrope (95° C.) takes place. The mixture is maintained for 6 h under reflux of the toluene (110° C.). After cooling, sodium hydrogen carbonate solution is added and the solution is then washed with saturated sodium chloride solution and dried over sodium sulfate. After concentration, 39 g of a yellow oil are obtained, which product is either distilled or chromatographed on a column of 215 g of silica (eluant: cyclo-hexane/ether, 98:2).

Herkunft & Nachweise