反应详情

To a solution of 5.6 g (50 mmol) of (1S,2S,5R)-2-methyl-6-oxabicyclo[3.1.0]hexan-3-one (4) in 400 ml of anhydrous methylene chloride was added 15 g of sodium bicarbonate and 12.9 g (64 mmol) of 85% m-chloroperbenzoic acid. The suspension was stirred at room temperature for 72 hr and filtered through Celite Filter-Aid. The filtrate was evaporated to dryness under reduced pressure, the residue was triturated with 40 ml of methylene chloride and insolubles were removed by filtration. The filtrate was washed twice with a saturated aqueous solution of sodium bicarbonate, dried over magnesium sulfate and evaporated to dryness under educed pressure. Heating at 70° (0.1 mm) removed 0.95 g of volatile material. The oily residue slowly crystallized on standing to give (1S,2S,6R)-2-methyl-3,7-dioxabicyclo[4.1.0]heptan-4-one: mp 51°-52°. Recrystallization from 12 ml of ether yielded end product: mp 51° -52°. Several recrystallizations from ether gave analytically pure (1S,2S,6R)-2-methyl-3,7-dioxabicyclo-[4.1.0]heptan-4-one: mp 52.5°-53.5°; [α]25D +147.26 (c 0.995, MeOH).

1. filtrationfiltered through Celite Filter-Aid
2. customThe filtrate was evaporated to dryness under reduced pressure
3. customthe residue was triturated with 40 ml of methylene chloride and insolubles
4. customwere removed by filtration
5. washThe filtrate was washed twice with a saturated aqueous solution of sodium bicarbonate
6. dry with materialdried over magnesium sulfate
7. customevaporated to dryness under educed pressure
8. temperatureHeating at 70° (0.1 mm)
9. customremoved 0.95 g of volatile material
10. customThe oily residue slowly crystallized