反応 #305184

反応方程式

ammonium chloride

THF

4-bromo-2,2-difluoro-1,3-benzodioxol

(±)-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c]isoxazole

→

title compound

(±)-(3aR*,7aS*)-7a-(2,2-difluorobenzo[1,3]dioxol-4-yl)hexahydropyrano[3,4-c]isoxazole

溶媒

toluene

toluene THF

反応条件

後処理

1. 1
   workup.ADDITIONa boron trifluoride-diethyl ether complex (990 μl) were added dropwise at the same time
2. 2
   その他to terminate
3. 3
   その他the reaction
4. 4
   抽出The aqueous layer was extracted with ethyl acetate
5. 5
   乾燥the organic layer was dried over anhydrous magnesium sulfate
6. 6
   その他The solvent was evaporated under reduced pressure
7. 7
   その他the residue was purified by silica gel column chromatography

実験手順

THF (2.0 ml) was added to a solution of 4-bromo-2,2-difluoro-1,3-benzodioxol (1.96 g) in toluene (20 ml). The mixture was cooled to −78° C., and a solution of (±)-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c]isoxazole obtained in Preparation Example 1-(2) (500 mg) in toluene-THF (10:1) (10 ml) and a boron trifluoride-diethyl ether complex (990 μl) were added dropwise at the same time. After stirring at the same temperature for two hours, an ammonium chloride solution was added to terminate the reaction. The aqueous layer was extracted with ethyl acetate, and the organic layer was dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography to obtain the title compound (873 mg).

出典