Metathesis and macrocycles with embedded carbohydrates

Macrocycles containing embedded carbohydrates are found in nature. Tricholorin A and G, woodrosin, sophorolipid lactone, cycloviracin B1, glucolipsin A and ipomoeassins A-F are natural products with interesting biological properties. They have inspired synthesis of non-natural macrocyclic structures which contain embedded carbohydrates. Glycophanes (hybrids of carbohydrates and cyclophanes) were prepared which show potential in host-guest chemistry and which have been applied as rigid scaffolds for the synthesis of bivalent inhibitors of lectin binding to tumour cells. Macrocyclic neoglycoconjugates have also been prepared. These include macrocyclic neooligoaminodeoxysaccharides which bind to RNA regions containing either asymmetric internal loop or hairpin loop-stem junctions, and vaccine candidates. Non-natural macrolides having antibacterial and antifungal activity have been synthesised. Metathesis using Grubbs and Hoyveda-Grubbs catalysts has been key to the successful generation of these compounds. Herein we review the recent application of metathesis to the synthesis of ipomoeassins A, B and F, glycophanes, neooligoaminodeoxysaccharides, macrolides and other macrocycles with embedded carbohydrates.