3(2H)-Furanone, dihydro-4-(hydroxymethylene)-2,2-dimethyl- (9CI) synthesis

Yield:142996-71-2 43%

Reaction Conditions:

palladium-carbon in ethanol;water;

Steps:

4 Synthesis of 1,2-bis[dihydro-2,2-dimethyl-3(2H)furanone-4-methyleneamino]ethane.

EXAMPLE 4 Synthesis of 1,2-bis[dihydro-2,2-dimethyl-3(2H)furanone-4-methyleneamino]ethane. Hydrogen gas was bubbled over the top of a iixture of 2,2-dimethyl-3(2H)furanone (5.0 g, 45 mmol) and 5% Pd/C (1.0 g) in 50 mL of water. After 24 hours, the starting material remained unchanged, so the mixture was transfered to a parr bottle and hydrogenated overnight at a pressure of 40 psi. The catalyst was removed by filtration and the aqueous solution was saturated with sodium chloride and extracted with ether. The combined ether layers were dried over MgSO₄, filtered and a large amount of the ether was distilled off through a short fractionating column to leave a 46 mol % or 56.5 wt % solution of dihydro-2,2-dimethyl-3(2H)furanone in ether (4.55 g, 90%). An ether solution of dihydro-2,2-dimethyl-3-(2H)-furanone; (4.55 g, 39.9 mmol) in -30 mL of ether was added dropwise to a suspension of sodium hydride (3.2 g of 60%, 80 mmol) in 150 mL of ether containing three drops of ethanol and 6.5 mL (80 mmol) of ethyl formate stirred at 0° C. After stirring overnight at room temperature, the reaction mixture was taken up into water, the ether layer separated, washed with additional ether, acidified with 6N HCl and extracted into ether. The combined ether layers were washed with water and brine, dried over MgSO₄, decolorized with charcoal, filtered and evaporated to leave 2.4 g of 4-hydroxymethylene-dihydro-2,2-dimethyl-3(2H)furanone as a colorless oil (43%).

References:

US5112594,1992,A