1,5-Diazabicyclo(5,4,0)undec-5-ene → HCID 21772271, compound

Participants

Reaction Steps

Methyl (5R,6R)-3-[(E)-2-acetamidoethenylthio]-6-[(S)-1-ethoxysulphonyloxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (e22) (86 mg) was taken up in dichloromethane (3 ml) and treated with 1,5-diazabicyclo[5.4.0]undec-5-ene (DBU) (33 mg) in dichloromethane (3.3 ml) added dropwise. After 15 minutes more DBU (3 mg) in dichloromethane (0.3 ml) was added and stirring was continued for 10 minutes. The solution was then washed with water (5 ml) and then chromatographed on silica gel to give methyl (5R,6E)-3-[(E)-2-acetamidoethenylthio]-6-ethylidene-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate and methyl (5R,6Z)-3-[(E)-2-acetamidoethenylthio]-6-ethylidene-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate as a mixture of isomers (e35 and e36) (21 mg), νmax (CH2Cl2) 1775 (broad), 1705, 1620 cm-1.

Provenance & Evidence