Reaktion #5083

Reaktionsgleichung

Acetic anhydride

Virginiamycin M1

→

monoacetate

diacetate

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefollowed by flash evaporation to dryness at room temperature
2. 2
   SonstigeThe residue was partitioned between dichloromethane (3×300 ml) and saturated NaCl (aq, 300 ml)
3. 3
   Trocknendried over anhydrous Na2SO4, flash
4. 4
   Sonstigeevaporated to dryness (dry weight=8.1 g)
5. 5
   Sonstigepurified over E

Vorschrift

Acetic anhydride (45 ml) was added to a stirring solution of Virginiamycin M1 (6.5 g) in anhydrous pyridine (45 ml) at room temperature. After 30 minutes, ice-cold methanol (85 ml) was added in portions. Stirring was continued for 20 more minutes followed by flash evaporation to dryness at room temperature. The residue was partitioned between dichloromethane (3×300 ml) and saturated NaCl (aq, 300 ml). The organic layers were pooled, dried over anhydrous Na2SO4, flash evaporated to dryness (dry weight=8.1 g) and purified over E. Merck silica gel 60 column in hexane/acetone mixtures to give 1.0 g of the monoacetate and 1.58 g of the diacetate.

Quelle