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

Reaction equation

[OH-:1].[Na+].S(=O)(=O)(O)O.[CH3:8][C:9]([CH:11]=[O:12])=[O:10].[C:13]1(C)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>>[O:10]=[C:9]([CH:11]([OH:12])[CH2:13][C:14](=[O:1])[CH2:15][CH2:16][C:17]#[CH:18])[CH3:8]

Participants

Reactant 4

HCID 880Methylglyoxal

HCID 1118Sulfuric Acid

HCID 1140Toluene

HCID 14798Sodium Hydroxide

Product 1

HCID 129396472,5-Dioxo-3-hydroxy-8-nonyneYield 82%

Conditions

Temperature: 30 °C

Procedure

To dimethyl 2-(2'-propynyl)-3-oxoglutarate (21.2 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 four times with ethyl acetate. The toluene layer and the ethyl acetate layer were combined, and the solvent was removed by evaporation to obtain 13.8 g of 2,5-dioxo-3-hydroxy-8-nonyne as a pale yellow oil (yield 82.0%).