Simplifying Oligosaccharide Synthesis: Efficient Synthesis of Lactosamine and Siaylated Lactosamine Oligosaccharide Donors
作者:Fengyang Yan、Seema Mehta、Eva Eichler、Warren W. Wakarchuk、Michel Gilbert、Melissa J. Schur、Dennis M. Whitfield
DOI:10.1021/jo026569v
日期:2003.3.1
A practical sequence is described for converting D-glucosamine into peracetylated Gal(beta-1,4)-GlcNTroc(beta1-S)Ph and Neu5Ac(alpha-2,3)Gal(beta-1,4)GlcNTroc(beta1-S)Ph building blocks using a synthetic strategy based on chemoenzymatic oligosaccharide synthesis. The known trichloroethoxycarbonyl, N-Troc, protecting group was selected as a suitable protecting group for both enzymatic and chemical reaction conditions. These oligosaccharide building blocks proved effective donors for the,beta-selective glycosylation of the unreactive OH-3 of a polymeric PEG-bound acceptor and for the axial OH-2 of a mannose acceptor in good yields. The resulting complex oligosaccharides are useful for vaccine and pharmaceutical applications.