反应详情

Potassium tert-butoxide (498 mg, 4.44 mmol) was added to a solution of (2-nitrobenzyl)triphenylphosphonium chloride (2.04 g, 4.89 mmol) in 1,4-dioxane (10 mL) under an atmosphere of argon. The mixture was stirred for 30 min at room temperature and then at 80° C. for 40 min. A solution of tert-butyl (4S)-4-formyl-2,2-dimethyl-oxazolidine-3-carboxylate (510 mg, 2.22 mmol) in 1,4 dioxane (3.0 mL) was added with a syringe. The resulting mixture was refluxed for 4 h and then allowed to come to room temperature overnight. The reaction mixture was poured into water and extracted with EtOAc (×3). The organic phases were combined and washed with brine and dried with MgSO4. The crude product was purified by flash chromatography eluting with petroleum ether/EtOAc 9:1 to afford a (Z)/(E) mixture of tert-Butyl (4R)-2,2-dimethyl-4-[2-(2-nitrophenyl)vinyl]-1,3-oxazolidine-3-carboxylate as a yellow oil. 288 mg of the obtained product was dissolved in EtOAc (10 ml), added Pd/C (40 mg, 10%) and then stirred under an atmosphere of hydrogen (1 atm) for 4 h. The reaction mixture was filtered through a pad of decalite and concentrated in vacuo. The crude product was purified by flash chromatography eluting with petroleum ether/EtOAc 2:1 to afford the title compound as a white solid.

1. waitat 80° C. for 40 min
2. temperatureThe resulting mixture was refluxed for 4 h
3. waitto come to room temperature overnight
4. extractionextracted with EtOAc (×3)
5. washwashed with brine
6. dry with materialdried with MgSO4
7. customThe crude product was purified by flash chromatography
8. washeluting with petroleum ether/EtOAc 9:1
9. customto afford a (
10. stirringstirred under an atmosphere of hydrogen (1 atm) for 4 h
11. filtrationThe reaction mixture was filtered through a pad of decalite
12. concentrationconcentrated in vacuo
13. customThe crude product was purified by flash chromatography
14. washeluting with petroleum ether/EtOAc 2:1