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

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.

1. customThe reaction mixture was quenched with isopropanol (0.5 ml) at 10°-20° C. for 15 minutes
2. additiondiluted with ethyl acetate (122 ml)
3. washwashed with water (135 ml)
4. customThe aqueous layer was separated from the organic layer
5. extractionextracted with ethyl acetate (61 ml)
6. extractionextracted with 5% aqueous sodium bicarbonate solution (30 ml)
7. washThe extract was washed with dichloromethane (60 ml)
8. temperaturecooling
9. extractionThe acidic solution was extracted twice with dichloromethane (60 ml)
10. washThe extracts were washed with brine
11. dry with materialdried over anhydrous sodium sulfate
12. filtrationAfter filtration
13. concentrationthe filtrate was concentrated in vacuo

ORD-Eintrag

ord-b76297b7782a4dedb693a126d3a0daab

Quelldatensatz

uspto-grants-1995_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05424422