Реакция #49998

Уравнение реакции

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

Растворители

acetone

Условия реакции

Обработка

1. 1
   ДругоеThe 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
   Промывкаwashed with water (135 ml)
4. 4
   ДругоеThe aqueous layer was separated from the organic layer
5. 5
   Экстракцияextracted with ethyl acetate (61 ml)
6. 6
   Экстракцияextracted with 5% aqueous sodium bicarbonate solution (30 ml)
7. 7
   ПромывкаThe extract was washed with dichloromethane (60 ml)
8. 8
   Температураcooling
9. 9
   ЭкстракцияThe acidic solution was extracted twice with dichloromethane (60 ml)
10. 10
    ПромывкаThe extracts were washed with brine
11. 11
    Сушкаdried over anhydrous sodium sulfate
12. 12
    ФильтрацияAfter filtration
13. 13
    Концентрированиеthe filtrate was concentrated in vacuo

Методика

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.

Источник