Methylglyoxal → 2,5-Dioxo-3-hydroxy-8-nonyne

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To diethyl 2-(2'-propnynyl)-3-oxoglutarate (24.0 g) was added a 10% aqueous sodium hydroxide solution (sodium hydroxide 8.0 g, water 72 ml) with ice cooling, followed by stirring at 30° C. for 5 hours. The pH of the reaction solution was adjusted to 7.5 with a 10% sulfuric acid with ice cooling, and toluene (60 ml) was added thereto. While passing nitrogen stream, a 40.7% aqueous methylglyoxal solution (20 g) was added dropwise to the reaction solution at 35° C. over 2 hours. Thereafter, the reaction solution was stirred at 35° C. for 15 hours. The reaction solution was separated into two layers, and the aqueous layer was saturated with sodium chloride and extracted three times with ethyl acetate. The toluene layer and the ethyl acetate layer were combined, and the solvent was removed by evaporation to obtain 14.1 g of 2,5-dioxo-3-hydroxy-8-nonyne as a pale yellow oil. Yield 83.8%. nD23 1.4593.

Herkunft & Nachweise