Methyl formate → 3-Oxo-cyclopentanecarboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

318.36 g (3 mol) of trimethylorthoformate are added gradually to a solution of 128.2 g (1 mol) of nonracemic 3-oxocyclopentanecarboxylic acid and 11.4 g (0.06 mol) of p-toluene sulfonic acid hydrate in 380 ml of methanol within 5-10 minutes while stirring, The mixture is heated and during 25 minutes a mixture of formic acid methyl ester and methanol is distilled off (about 185 g of distillate), Thereafter 29 g of 30% sodium methylate solution (0.16 mol) are added and the reaction mixture is kept boiling under reflux for 2 hours; methanol is distilled off, the residue cooled to 10° C. and dissolved by adding 230 ml of methylene chloride and 200 ml of water. By adding 5% sulfuric acid the mixture is adjusted to pH 1.4 and stirred at 10° C. for 30 minutes. The methylene chloride phase is separated and the aqueous phase extracted again with 100 ml of methylene chloride. The combined organic phases are stirred with 50 ml of water, separated and the solvent is distilled off in vacuo. The residue is fractionated in vacuo.

Herkunft & Nachweise