Reaktion #74891

Reaktionsgleichung

(1S,2S,5R)-2-methyl-6-oxabicyclo[3.1.0]hexan-3-one

sodium bicarbonate

m-chloroperbenzoic acid

→

(1S,2S,6R)-2-methyl-3,7-dioxabicyclo[4.1.0]heptan-4-one

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationfiltered through Celite Filter-Aid
2. 2
   SonstigeThe filtrate was evaporated to dryness under reduced pressure
3. 3
   Sonstigethe residue was triturated with 40 ml of methylene chloride and insolubles
4. 4
   Sonstigewere removed by filtration
5. 5
   WaschenThe filtrate was washed twice with a saturated aqueous solution of sodium bicarbonate
6. 6
   Trocknendried over magnesium sulfate
7. 7
   Sonstigeevaporated to dryness under educed pressure
8. 8
   TemperaturHeating at 70° (0.1 mm)
9. 9
   Sonstigeremoved 0.95 g of volatile material
10. 10
    SonstigeThe oily residue slowly crystallized

Vorschrift

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).

Quelle