反应详情

Sodium hydroxide (65 g, 1.625 moles) in 65 g H2O was added over a period of one hour to a stirring solution of ethyl acetoacetate (192 g, 1.47 moles), 1,2-butylene oxide (120 g, 1.66 moles) and H2O (470 g) in a two liter, four-neck flask equipped with a mechanical stirrer, thermometer, addition funnel, and condenser. The reaction was run at about 25° C. for three hours. The mixture was transferred to a separatory funnel and acidified with 155 g 20° Baume hydrochloric acid. The organic fraction (182.6 g) was placed on a Rotovap and stripped at 60° C. and 15 torr to yield 151.8 g residue and 29.5 g distillate. The main fraction (151.8 g) and a methylene chloride extract (32 g) of the aqueous phase were distilled using a Raschig ring packed column and a Perkins Triangle Head as in Example I. Three fractions were obtained upon distillation. Fraction 1 contained mostly unreacted ethyl acetoacetate. Fraction 2 (7.6 g) had a boiling point of 90-100° C. at 2 torr and contained 86.6% of the desired furanone product. Fraction 3 (88.3 g) boiled in the range 100-160° C. at 2 torr and contained 93.4% lactone. Total yield of lactone was 90.4 g or 39.3%.

1. extractionThe main fraction (151.8 g) and a methylene chloride extract (32 g) of the aqueous phase
2. distillationwere distilled
3. customThree fractions were obtained upon distillation
4. customboiled in the range 100-160° C. at 2 torr