[C:1]([OH:9])(=[O:8])[CH:2]([CH2:4][C:5]([OH:7])=[O:6])[OH:3].[CH3:10][CH:11]([CH3:15])[CH2:12][CH2:13]O>>[CH2:13]([O:8][C:1](=[O:9])[CH:2]([CH2:4][C:5]([O:7][CH2:13][CH2:12][CH:11]([CH3:15])[CH3:10])=[O:6])[OH:3])[CH2:12][CH:11]([CH3:15])[CH3:10]Diisoamyl-DL-malate was prepared using a procedure similar to that in Example 4. To the reaction flask, DL-malic acid (87.54 g), 3-methyl-1-butanol (285 mL) and Amberlyst® 15 ion exchange resin (11.9) were added. The mixture was placed under nitrogen and heated to reflux. At 109° C., two phases started to collect in the Dean-Stark trap. The reaction was maintained at 110° C. for 8 hr, during this time water was continuously removed. The product was dissolved in diethyl ether and separated from the catalyst via filtration over a bed of silica. The organic layer was washed with saturated sodium bicarbonate a number of times, washed once with water, and dried over magnesium sulfate. Diethyl ether was removed via rotary evaporation. Diisoamyl-DL-malate was obtained as a low viscosity, clear colorless liquid with a slight odor (130 g, 72% yield) after pumping on the sample in vacuo to remove residual 3-methyl-1-butanol.
読み込み中…