Electrochemical bromochlorination of peracetylated glycals.
Peracetylated glycals-3,4,5-tri-O-acetyl-D-glucal (1a), 3,4,5-tri-O-acetyl-D-galactal (1b) and 3,4-di-O-acetyl-6-deoxy-L-glucal (1c)-have been bromochlorinated by a suitable halogenating agent, generated electrochemically from a mixture of bromides and chlorides in dichloromethane. The reaction was performed in two ways: (i) by a constant current electrolysis (2Fmol(-1)) of bromides and substrates in a milieu containing an excess of chlorides (Br(θ)/1/Cl(θ)=1:1:6.8) and (ii) by anodic generation of free chlorine from chlorides (2Fmol(-1)) and subsequent addition of bromides and substrates in a ratio Br(θ)/1=1:1. The corresponding 2-bromo-2-deoxy-glycopyranosyl chlorides were obtained in high yields.
Department of Chemistry, Faculty of Science, University of Kragujevac, R. Domnovića 12, 34000 Kragujevac, Serbia.
Ivan
I
Damljanović
Dragana
D
Stevanović
Mirjana
M
Vukićević
Rastko D
RD
Vukićević
D000085:Acetates / Q000138:chemical synthesis* / Q000737:chemistry; D001965:Bromides / Q000138:chemical synthesis* / Q000737:chemistry; D002712:Chlorides / Q000138:chemical synthesis* / Q000737:chemistry; D004572:Electrolysis; D005690:Galactose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D005947:Glucose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D054879:Halogenation; D019789:Tetraethylammonium / Q000737:chemistry
D000085:Acetates; D001965:Bromides; D002712:Chlorides; D019789:Tetraethylammonium; D005947:Glucose; D005690:Galactose