Metathesis of structurally preorganized bivalent carbohydrates. Synthesis of macrocyclic and oligomeric scaffolds

[reaction: see text] Bivalent carbohydrate substrates for metathesis were synthesized from glucuronic acid and phenylene-1,4-diamine. The substrate secondary structure depends on whether secondary or tertiary amides are present, and this influences the course of the metathesis reaction leading to novel multivalent scaffolding. Molecular modeling suggests that a very rigid macrocyclic scaffold has potential for the development of alpha-helix peptidomimetics.