Therapeutic efficacy of nucleoside analogues (NAs) like Gemcitabine, 5-fluorouracil in cancer treatment is already well established. Most of the known NAs are highly toxic to normal cells due to its non-specific action; thus searching for non-toxic NAs are still going on. For that purpose we have synthesised nine different NAs by alteration of their structural and functional groups.
View Article and Find Full Text PDFIntramolecular nitrone cycloaddition (INC) reaction on a d-glucose derived substrate carrying an allyl group at C-1 and an enose-nitrone at C-5 or an aldehyde-nitrone at C-1 and vinyl group at C-4 furnished a tricyclo[6.2.1.
View Article and Find Full Text PDFInstalling hydroxymethyl and hydroxyethyl substitutions at C-4 through vinylation and hydroboration-oxidation reactions of the C-4 bis-hydroxymethyl derivative of d-glucose based substrate, and inserting heteroatoms thereafter permitted formation of N-, O-, or S-heterocycles leading to [4,5]- or [5,5]-spirocycles and a bicyclo[3.3.0]octane product.
View Article and Find Full Text PDFTreatment of the d-glucose-derived substrate 1 with sodium hydride in tetrahydrofuran provided 3,6-anhydro monosaccharide 2, along with the 5,6-ether linked pseudodisaccharide 3, and pseudotrisaccharide 4. However, reaction of 1 with sodium ethoxide in ethanol afforded 2 as the sole product, elaborated to the bicyclic azidonucleosides 9 and 16. Acetylated bicyclic nucleosides 17-19 with extended carbohydrate residues have been synthesized from 3.
View Article and Find Full Text PDFThe dioxepanofuranose derivatives 4 and 12, obtained through the cyclization of the 3-(2-hydroxyethyl) ether of a D-xylo-pentodialdose derivative, were appropriately functionalized and elaborated to the first examples of the new class of 3'-O and 5'-O-bicyclic nucleoside analogues 9, 10, and 14 with a fused seven-membered ring. Reactions carried out through the intermediacy of the D-xylo-pentodialdose derivative 5 yielded racemic products, while prior protection of the 4-formyl group (as in 7) before deprotection of the 1,2-hydroxyl groups led to optically active analogues.
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