Synthesis and characterization of 1- O-β-lactosyl-( R,S)-glycerols and 1,3-di- O-β-lactosylglycerol

• Published in: Carbohydrate research 1989-07, Vol.190 (2), p.203-218
• Main Authors: Hronowski, Lucjan J.J., Szarek, Walter A., Hay, George W., Krebs, Anita, Depew, William T.
• Format: Article
• Language: English
• Subjects: Carbohydrates with 4, 5, 6, ... C atoms, dissacharides and oligosaccharides; Carbohydrates. Nucleosides and nucleotides; Chemistry; Exact sciences and technology; Organic chemistry; Preparations and properties
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/0008-6215(89)84126-6

The synthesis of 1- O-β-lactosyl-( R,S)-glycerols was achieved by three methods: ( a) in 25% yield by the trimethylsilyl trifluoromethanesulfonate-promoted reaction of octa- O-acetyl-β-lactose ( 11) with ∼0.5 mol-equiv. of 2- O-benzylglycerol ( 4), ( b) in ∼34% yield by the coupling of 4 with an equimolar amount of hepta- O-acetyl-α-lactosyl bromide ( 12) in the presence of mercury(II) cyanide, and ( c) in ∼50% yield by the coupling of equimolar amounts of 12 and 1,2-di- O-benzyl-( R,S)-glycerols in the presence of mercury(II) cyanide, followed in each case by the removal of the blocking groups. 1,3-Di- O-β-lactosylglycerols were prepared in 21% yield by the coupling of 11 with ∼0.5 mol-equivalent of 4 by method ( a), and in 38% yield by the coupling of 12 with ∼0.5 mol-equiv. of 4 by method ( b), followed by the removal of the blocking groups. The configuration of the glycosidic linkage between the lactose units and the glycerol residue was established by high-resolution, two-dimensional 1H-n.m.r. spectroscopy.