反応 #49991

反応方程式

sodium hydroxide

(3S,4S)-4-carboxy-3-(1-(R)-hydroxyethyl)-1-di(p-anisyl)methyl-2-azetidinone

sulfuric acid

methanol

→

(3S,4S)-4-methoxycarbonyl-3-(1-(R)-hydroxyethyl)-1-di(p-anisyl)methyl-2-azetidinone

反応条件

後処理

1. 1
   濃縮concentrated
2. 2
   workup.ADDITIONThe concentrate was diluted with 1,2-di-chloroethane (105 ml)
3. 3
   洗浄washed with water
4. 4
   その他The aqueous layer was separated from the organic layer
5. 5
   抽出extracted with 1,2-dichloroethane (105 ml)
6. 6
   洗浄washed with water
7. 7
   乾燥dried over anhydrous sodium sulfate
8. 8
   ろ過After filtration
9. 9
   濃縮the filtrate was concentrated in vacuo

実験手順

To a solution of (3S,4S)-4-carboxy-3-(1-(R)-hydroxyethyl)-1-di(p-anisyl)methyl-2-azetidinone (34 g) in methanol (310 ml), there was added 98% sulfuric acid (2.9 g). The resultant mixture was heated at 65° C. for 3 hours, cooled down to 40° C., neutralized with 8% aqueous sodium hydroxide solution (15 ml) and concentrated to make a one third volume. The concentrate was diluted with 1,2-di-chloroethane (105 ml) and washed with water. The aqueous layer was separated from the organic layer and extracted with 1,2-dichloroethane (105 ml). The extract was combined with the organic layer, washed with water and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo to give (3S,4S)-4-methoxycarbonyl-3-(1-(R)-hydroxyethyl)-1-di(p-anisyl)methyl-2-azetidinone. m.p., 102°-104° C.

出典