PREPARATION OF NEW OPTICALLY-ACTIVE FURANOIDS CONTAINING VARIOUS AZA-HETEROCYCLIC MOIETIES

The aldehyde 2 prepared from a-D-erythrofuranosyl)-2-methylfuran-3-yl] -methanol (1) was converted to E,Z-oximes 3, 4 and imine derivative 5 by the reaction with hydroxylamine and pyridin-2-yl amine, respectivel y. The Knoevenagel reaction with malonic acid afforded exclusively the 3-substituted acrylic acid 6 while corresponding Hantzsch 1,4-dihydro pyridines 7 and 8 were obtained by the reaction of aldehyde 2 with eth yl acetoacetate or acetylacetone and ammonia, 3,5-Dicyano-1,4-dihydrop yridine derivative 9 was isolated only in forms of hydrates after the reaction of aldehyde 2 with 3-aminocrotonitrile. 1,4-Dihydropyridines 7 and 9 were aromatized to corresponding pyridines 10 and 11. Isoxazol es 12, and 13 and isoxazolines 14, 15 were prepared by 1,3-cycloadditi on of appropriate dienophiles to a nitrile oxide generated from aldoxi mes 3, 4. Ferricyanide oxidation of rofuranosyl)-2-methylfuran-3-yl]me thyl}-pyridinium chloride (17a), -3-methylpyridinium chloride (19a) an d the corresponding isoquinolinium chloride 21a gave optically active pyridine-2(1H)-ones 22, 23 and 2H-isoquinolone derivative 24 while the procedure with 2-methylpyridinium salt 18a and 4-methylpyridinium sal t 20a led to complex mixtures of products. Reaction of 2,4,6-triphenyl pyrylium perchlorate with furanoid amine 26 afforded a mixture of majo r 2,4,6-triphenylpyridine, minor pyridinium perchlorate 25 and primary alcohol 1. The absolute configuration of the studied compounds has be en confirmed by X-ray analysis of the Schiff base 5.