In situ proton NMR study of acetyl and formyl group migration in mono-O-acyl D-glucose.
Acetyl and formyl group migration, mutarotation, and hydrolysis of mono-O-acylated glucose are studied by in situ 1D and 2D (1)H NMR spectroscopy. Alpha-D-glucosyl-1-acetate and alpha-D-glucosyl-1-formate serve as sole starting materials. They are generated in situ by configuration retaining glucosyltransfer from alpha-D-glucosyl-1-phosphate to formate and acetate, which is catalyzed by the Glu-237 --> Gln mutant of Leuconostoc mesenteroides sucrose phosphorylase. Temporary accumulated regio-isomeric mono-O-acyl D-glucoses are identified, characterized, and quantified directly from the reaction mixture. Time courses of the transformations give insight into pH dependence of acyl group migration and mutarotation as well as into the stability of various regioisomers.
Brecker
Lothar
L
University of Vienna, Department of Organic Chemistry, Währinger Strasse 38, A-1090 Wien, Austria. lothar.brecker@univie.ac.at
Mahut
Marek
M
Schwarz
Alexandra
A
Nidetzky
Bernd
B
D000085:Acetates / Q000737:chemistry*; D000107:Acetylation; D002236:Carbohydrate Conformation; D005561:Formates / Q000737:chemistry*; D005947:Glucose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D011522:Protons; D013997:Time Factors
D000085:Acetates; D005561:Formates; D011522:Protons; D005947:Glucose