Carbohydrates containing additional rings

Replacement by carbon 2-Carb-35. Carbohydrates containing additional rings... 

In addition, bifunctionalized carbohydrate derivatives containing simultaneously one azido and alkyne groups have been intermoleculary reacted, affording cyclic carbohydrate-containing molecule of interest that also possess more that one triazole ring in their structures. 

Carbohydrates containing C-phosphorus linkages including those with phosphorus in the ring have been synthesized via addition of phosphorus nucleophiles to 6-nitro-xy/o-hex-5-enofuranose derivatives (Schemes 10 and 11). The acetyl migration of (25) to yield (26) occurred spontaneously. ... 

The use of complex radical donors and radical acceptors, such as carbohydrates tethered by an acetal-containing linkage, has been reported by Sinay [98]. Here, the radical addition of an anomeric radical to a 4-exo-methylene sugar derivative (compound 69) proceeds in the 8-endo mode, with formation of a eight-membered acetal ring. The end product of this reaction, after removal of the tether and acetylation, is the C-disaccharide 70 (Scheme 27). 

Two representatives of a remarkable new class of glycosans containing the < 1,4 > < 1,6 > (1,6-anhydrohexofuranose) ring system recently have been isolated as additional products of the pyrolytic vacuum distillation of carbohydrates. From starch, Dimler, Davis and Hilbert7 obtained... 

The reaction of carbonyl compounds and allylmetal reagents is an important transformation in organic synthesis. Advances in stereoselective carbonyl allylation reactions have been spurred by interest in the synthesis of polypropionate-derived natural products, carbohydrates and other polyhydroxylated compounds. These reactions are ideally suited for the construction of stereochemically rich acyclic skeletons. Additionally, cyclic polyether-containing natural products, among others, have inspired chemists to investigate ring-closing allylation reactions. This review will focus on recent developments in the allylation reaction, with special emphasis on its application towards the synthesis of natural products. 

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