Reaction #632036

Reaction equation

hydroxylamine

water

( 29 )

(3R,4R)-2,5-Dioxo-3,4-dibenzoyloxy-3,4-dihydrofuran

acetonitrile

→

title compound ( 30 )

Yield 87.1%

1-Hydroxy-(3R,4R)-2,5-Dioxo-3,4-dibenzoyloxypyrrolidine

Yield 87.1%

Solvents

toluene

Conditions

Workup

1. 1
   OtherTo a 3-neck 5 L round bottom flask fitted with a mechanical stirrer
2. 2
   workup.DISSOLUTIONThe starting material gradually dissolved during the addition
3. 3
   Temperaturethe reaction mixture was warmed to 20° C.
4. 4
   ConcentrationThe reaction mixture was concentrated in vacuo
5. 5
   workup.ADDITIONdiluted with EtOAc (1 L)
6. 6
   Washwashed with 1 N HCl (2×1 L)
7. 7
   OtherThe organic phase was separated
8. 8
   Concentrationconcentrated in vacuo
9. 9
   Otherto afford a viscous red syrup
10. 10
    workup.DISSOLUTIONThe syrup gradually dissolved
11. 11
    Otherthe product crystallized
12. 12
    TemperatureAfter cooling to room temperature the solid
13. 13
    Filtrationwas collected by filtration
14. 14
    Washwashed with 10% acetone in hexane (2×1 L)
15. 15
    Otherdried in a vacuum oven

Procedure

To a 3-neck 5 L round bottom flask fitted with a mechanical stirrer and a Teflon coated temperature probe was added (29) (2.79 mol) followed by acetonitrile (2 L). The suspension was cooled in an ice bath to 4° C., followed by the addition of 50% aqueous hydroxylamine (180 mL, 2.93 mol) over 1 h. The starting material gradually dissolved during the addition and the reaction mixture was warmed to 20° C. and stirred for 1 h. The reaction mixture was concentrated in vacuo, diluted with EtOAc (1 L) and washed with 1 N HCl (2×1 L). The organic phase was separated and concentrated in vacuo to afford a viscous red syrup. The syrup was then heated for two hours in toluene (2.5 L) at 100° C. with azeotropic removal of water. The syrup gradually dissolved and then the product crystallized. After cooling to room temperature the solid was collected by filtration, washed with 10% acetone in hexane (2×1 L) and dried in a vacuum oven to afford the title compound (30) (862 g, 2.43 mol, 87% yield) as a white solid. 1H NMR (CDCl3, 400 MHz): δ 5.85 (s, 2H), 7.45 (app. t, 4H), 7.65 (app t, 2H), 8.05 (m, 4H).

Source