Реакция #74891

Уравнение реакции

(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

Растворители

methylene chloride

Условия реакции

Обработка

1. 1
   Фильтрацияfiltered through Celite Filter-Aid
2. 2
   ДругоеThe filtrate was evaporated to dryness under reduced pressure
3. 3
   Другоеthe residue was triturated with 40 ml of methylene chloride and insolubles
4. 4
   Другоеwere removed by filtration
5. 5
   ПромывкаThe filtrate was washed twice with a saturated aqueous solution of sodium bicarbonate
6. 6
   Сушкаdried over magnesium sulfate
7. 7
   Другоеevaporated to dryness under educed pressure
8. 8
   ТемператураHeating at 70° (0.1 mm)
9. 9
   Другоеremoved 0.95 g of volatile material
10. 10
    ДругоеThe oily residue slowly crystallized

Методика

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).

Источник