Ezomycins synthesis

An overview of various synthetic approaches to bicyclic nucleosides such as the octosyl acids and the ezomycins is presented. Details of the total synthesis of octosyl acids A and C are disclosed. 

Hanessian, S, Liak, T J, Dixit, D M, Synthesis of trans-fused perhydrofuropyrans and related a-methylene lactones bicyclic ring-systems present in the ezomycins, the octosyl acids, and certain antitumor terpenoids, Carbohydr. Res., 88, C14-C19, 1981. 

Ogawa later published the synthesis of a 3-amino-3,4-dideoxyhexiu-onic acid in route to ezomycin [24]. In that account, a 1,6-anhydro epoxy sugar was reacted with sodium azide followed by antimony pentachloride to give methyl 3-azido-2-0-benzoyl-a-D-glucospyranoside. Oxidation of the primary alcohol was achieved with potassium permanganate, and reduction of the azide was accomplished with hydrogenation (Fig. 8). 

A synthesis of the octose moiety of ezomycin A from D-galactal 93... 

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