Development of a new glycosidation method to obtain 2-deoxy-beta-glycosides, and study of syntheses of the trisaccharide chain in the aureolic acid.

摘要

Part 1. An innovative method for the syntheses of 2-Deoxy-beta-glycosides was developed. A bicyclic glycosyl donor was formed through a hetero Diels-Alder reaction. This 1,4 oxathiin system formed in the Diels-Alder reaction was used to obtain a disaccharide through conventional activation in the presence of a suitable acceptor. Reduction of the sulfur at C2 of the donor unit in the disaccharide by treatment with Ra-Ni produced 2- deoxy-glycosides in good yield. Studies on the novel stereoelectronic behavior of the bicyclic glycosyl donors were conducted.;Part 2. The glycosidation method developed in part 1 was applied to a study of the syntheses of the trisaccharide unit present in the aureolic acid. Several cycloadducts were synthesized and the stereoselectivity of hetero Diels-Alder reactions was studied.