반응 #87470

반응 방정식

(1S,2S,3S,4R,5S)-5-[4-Chloro-3-(4-ethoxy-benzyl)-phenyl]-1-hydroxymethyl-6,8-dioxa-bicyclo[3.2.1]octane-2,3,4-triol

acetyl chloride

methanol

→

product

수율 87.0%

Acetic acid (1R,2S,3S,4R,5S)-5-[4-chloro-3-(4-ethoxy-benzyl)-phenyl]-2,3,4-trihydoxy-6,8-dioxa-bicyclo[3.2.1]oct-1-ylmethyl ester

수율 87.0%

용매

collidine

반응 조건

후처리

1. 1
   농축The crude mixture was concentrated under reduced pressure
2. 2
   기타The crude material was purified by flash chromatography over silica gel using the biotage
3. 3
   세척eluting with a gradient of 0 to 15% methanol in dichloromethane

실험 절차

To a vigorously stirred solution of (1S,2S,3S,4R,5S)-5-[4-Chloro-3-(4-ethoxy-benzyl)-phenyl]-1-hydroxymethyl-6,8-dioxa-bicyclo[3.2.1]octane-2,3,4-triol (1A, 0.481 g, 1.1 mmol) in collidine (2.5 mL) cooled to −35 degrees Celsius was added drop-wise over 10 minutes acetyl chloride (0.149 mL, 2.1 mmol). After 1 hour, methanol (0.5 mL) was added and the reaction mixture was allowed to warm to room temperature. The crude mixture was concentrated under reduced pressure and codistilled three times with toluene. The crude material was purified by flash chromatography over silica gel using the biotage automated chromatography unit (50 g silica gel column) and eluting with a gradient of 0 to 15% methanol in dichloromethane. 456 mg (87% yield) of product obtained as a white solid.

출처