Building blocks from monosaccharides for synthesis of scaffolds, including macrocycles. Application of allylic azide rearrangement, azide-alkyne cycloaddition and ring closing metathesis

Abstract

Synthesis of compounds with characteristics of natural products are required to increase the diversity and biological relevance of compounds for screening. These include new frameworks/scaffolds, with multiple stereogenic centres and various functional groups. Carbohydrates are renewable, readily available and have stereochemical diversity and functionality. Herein, building blocks derived from monosaccharides with alkene, alkyne and organic azide functional groups are used. The build-couple-pair strategy of diversity oriented synthesis is employed taking advantage of RuAAC, CuAAC and thermally promoted azide-alkyne cycloadditions, allylic azide (Winstein) rearrangement and ring closing metathesis, leading to polyhydroxylated small, medium and macrocyclic ring containing scaffolds. There is potential to graft appendages (e.g. pharmacophoric groups) to further increase diversity of compounds available for screening, or to consider the scaffolds in ligand design.