反应详情

A stirred solution of selenium dioxide (2.10 g, 18.91 mmol) in moist dioxane (17 ml, containing 0.5% distilled water by volume) is heated to 100° C., at which point a second (mixed) solution of 5-methoxymethyl-2,2,5-trimethyldihydrofuran-3-one and 2-methoxymethyl-2,5,5-trimethyldihydrofuran-3-one (2.55 g, 14.82 mmol) in moist dioxane (5 ml, containing 0.5% distilled water by volume) is added dropwise over 40 minutes, then further heated at this temperature for 3 hours. After cooling to room temperature the mixture is filtered through diatomaceous earth (washing with diethyl ether) then the solvents are removed at 40° C./50 mbar to give a viscous red-brown oil. This material is purified by bulb to bulb distillation to afford 2-methoxymethyl-2,5,5-trimethylfuran-3,4-dione (2.15 g) as a bright red oil.

1. additionis added dropwise over 40 minutes
2. temperaturefurther heated at this temperature for 3 hours
3. filtrationis filtered through diatomaceous earth (washing with diethyl ether)
4. customthe solvents are removed at 40° C./50 mbar
5. customto give a viscous red-brown oil
6. distillationThis material is purified by bulb to bulb distillation