Ruthenium Carbenoids as Catalysts for Olefin Metathesis of ω-Alkenyl Glycosides

Publisher Summary Olefin metathesis is a powerful synthetic process that translates, in its most simplified version, into the combination of two alkenes to generate a new double bond among the reacting partners with the evolution of ethylene gas when dealing with terminal alkenes. The procedure can lead to self- and cross-metathesis, ring-closing metathesis, and ring-opening metathesis polymerization. The most widely used catalysts for this process are transition metal carbenoids. Carbohydrate derivatives with allyl ethers, as well as with O- and C-linked allyl glycosides, have been known for a long time, and several of these derivatives are well-established precursors in synthetic carbohydrate chemistry. Obviously, olefin metathesis in its various forms represents a particularly appealing chemical process for the design of small carbohydrate clusters (e.g., dimers), glycomimetics, conformationally restrained oligosaccharides, and perhaps, more importantly, functionalized aglycones with pendant functionalities suitable for further neoglycoconjugate syntheses. This chapter reports some of the applications in which the terminal alkene groups have been introduced in key positions around the ring.