SYNTHESIS OF 1,2-trans-DISACCHARIDES via SUGAR THIO-ORTHOESTERS

Article abstract of DOI:10.1016/S0008-6215(00)84672-8

The reaction of sugar 1,2-thio-orthoesters in the D-gluco, D-galacto, D-manno, and L-rhamno series with primary and secondary trityl ethers of monosaccharides, in the presence of triphenylmethylium perchlorate as catalyst, affords, stereospecifically, derivatives of 1,2-trans-disaccharides in good yields. 4-Trityl ethers of benzyl 2-acetamido-3,6-di-O-acetyl-2-deoxy-α-D-glucopyranoside and methyl 2,3,6-tri-O-benzoyl-α-D-galactopyranoside exhibit low reactivity in glycosylation by thio-ortho-esters.A reaction scheme for the glycosylation is discussed.