Reacción #49998

Ecuación de reacción

sulfuric acid

water

(3S,4S)-4-(1-(R)-hydroxymethylethyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-2-azetidinone

Jones reagent

→

(3S,4S)-4-(1-(R)-carboxyethyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-2-azetidinone

Disolventes

acetone

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe reaction mixture was quenched with isopropanol (0.5 ml) at 10°-20° C. for 15 minutes
2. 2
   workup.ADDITIONdiluted with ethyl acetate (122 ml)
3. 3
   Lavadowashed with water (135 ml)
4. 4
   OtroThe aqueous layer was separated from the organic layer
5. 5
   Extracciónextracted with ethyl acetate (61 ml)
6. 6
   Extracciónextracted with 5% aqueous sodium bicarbonate solution (30 ml)
7. 7
   LavadoThe extract was washed with dichloromethane (60 ml)
8. 8
   Temperaturacooling
9. 9
   ExtracciónThe acidic solution was extracted twice with dichloromethane (60 ml)
10. 10
    LavadoThe extracts were washed with brine
11. 11
    Secadodried over anhydrous sodium sulfate
12. 12
    FiltraciónAfter filtration
13. 13
    Concentraciónthe filtrate was concentrated in vacuo

Procedimiento

A solution of (3S,4S)-4-(1-(R)-hydroxymethylethyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-2-azetidinone (6.1 g) in acetone (60 ml) was treated with the Jones reagent, prepared from chromium trioxide (2.78 g), 98% sulfuric acid (4.4 g) and water (8.1 ml), at 10°-20° C. for 1 hour. The reaction mixture was quenched with isopropanol (0.5 ml) at 10°-20° C. for 15 minutes, diluted with ethyl acetate (122 ml) and washed with water (135 ml). The aqueous layer was separated from the organic layer and extracted with ethyl acetate (61 ml). The ethyl acetate extracts and the organic layer were combined together and extracted with 5% aqueous sodium bicarbonate solution (30 ml). The extract was washed with dichloromethane (60 ml) and acidified with 10% hydrochloric acid solution (20 ml) with ice-cooling. The acidic solution was extracted twice with dichloromethane (60 ml). The extracts were washed with brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo to give (3S,4S)-4-(1-(R)-carboxyethyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-2-azetidinone.

Fuente