Carbocycles from carbohydrates via

Martinez-Grau, A. et al. Carbocycles from Carbohydrates via Free Radical Cyclization New Synthetic Approaches to Glycomimetics. 1998 [93]... 

T. K. M. Shing, D. A. Elsley, and J. G. Gillhouley, A rapid entry to carbocycles from carbohydrates via intramolecular nitrone cycloaddition, J. Chem. Soc. Chem. Commun. (1989) 1280-1282. 

Marco-Contelles, J, Martinez-Grau, A, Carbocycles from carbohydrates via free radical cycbzations New synthetic approaches to glycomimetics, Chem. Soc. Rev., 27, 155-162, 1998. 

C. S. Wilcox and L. M. Thomasco, New syntheses of carbocycles from carbohydrates. Cycliza-tion of radicals derived from unsaturated halo sugars, J. Org. Chem. 50 546 (1985) see also S. Hanessian, D. S. Dhanoa, and P, L. Beaulieu, Synthesis of tt-substituted a,P-unsaturated esters via radical-induced cyclizations, Can. J. Chem. 65 1859 (1987). 

Preparation of highly functionalized medium-sized carbocycles (210) and (212), derived from carbohydrates, can also be carried out with the same procedure via 8-endo-trig and 1-exo-trig manners, as shown below (eqs. 3.81, 3.82). Moreover, preparation of (3-C-disaccharide (214) proceeds selectively via 8-endo-trig radical cyclization of two temporarily tethered monosaccharide (213), by means of the addition of a carbohydrate-... 

J. Marco-Contelles, C. Destabel, P. Gallego, J. L. Chiara, and M. Bemabe, A new synthetic approach to the carbocyclic core of cyclopentane-type glycosidase inhibitors Asymmetric synthesis of amino-cyclopentitols via free radical cycloisomerization of enantiomerically pure alkyne-tethered oxime ethers derived from carbohydrates, J. Org. Chem., 61 (1996) 1354-1362. 

A related carbocycle is synthesized starting from carbohydrate precursors. The radicals are generated via Barton deoxygenation of the intermediate 5-heptenolsiei. The effect of 1-, 2-, 3-and 4-substituents on the stereoselectivity of the cyclization reaction has also been described 17-18. The formation of the 1,5-m-product is rationalized by the Beckwith modelThe 4,5-configuration of the main product is tram and is explained by the influence of allylic strain. 

Cycloaddition reactions have been used for the annulation of carbocyclic rings onto carbohydrate templates. The butenolide (6), derived from D-ribonolactone, gave the potential prostacyclin syn-thon (7) via reaction with butadiene and the chrysanthemic acid... 

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