The direct conversion of 5′-O-trityl-3′-keto-2′-deoxythymidine to 1-(2-deoxy-3-methyl-beta-D-xylosyl)thymine

C-3‘-Branched Thymidines as Precursors for the Selective Generation of C-3‘-Nucleoside Radicals

“…Even though considerable attention has been devoted to the synthesis of C-3‘-branched nucleosides, only a few examples of C-3‘-branched deoxynucleoside analogues with both a 3‘-α-hydroxy group and a 3‘-β-carbon substituent can be found in the literature . Via the most obvious method for the generation of these derivatives, the addition of a carbon nucleophile to a 3‘-ketonucleoside, it has been observed that mainly the threo- configured nucleoside analogues are obtained . Wengel et al10c used this preference for α attack to generate nucleoside derivatives with a hydroxymethyl substituent by bishydroxylation of the corresponding C-3‘-methylidene nucleoside derivatives.…”

Iodine Monochloride Facilitated Deglycosylation, Anomerization, and Isomerization of 3-Substituted Thymidine Analogues

“…In general, 3′-keto-2′-deoxy-nucleosides are prone to β-elimination of their nucleobase [42] and it is conceivable that ICl causes oxidation of the 3′-hydroxyl group in compounds 1 and 9 , which subsequently can lead to loss of thymine/3-alkylthymines. However, the reaction of 3′,5′-di- O -methyl-3-butyl-β-thymidine ( 6 ) with ICl led to substantial formation of 3-butylthymine ( 2 ) and 3′,5′-di- O -methyl-3-butyl-α-thymidine ( 7 ), which cannot occur via oxidation of the 3′-hydroxyl group and subsequent β-elimination.…”

Structure of a modified nucleoside, 3'α-diethylphosphono-3'β-hydroxy-5'-O-tritylthymidine

“…There have been few studies of nucleophilic additions to keto nucleosides (Webb, 1988;P&ez-P~rez, San-Frlix, Camarasa, Balzarini & De Clercq, 1992) and most have relied upon NMR studies, particularly NOE experiments, to determine stereochemistry (Bender & Moffett, 1992;Grouiller, Essadiq, Pacheco, Juntunen & Chattopadhyaya, 1985). Our studies on nucleophilic addition of phosphorus reagents to keto nucleosides provided single crystals of one of the synthetic targets, (I); its crystal structure determination allowed the unambiguous assignment of the stereochemistry at C(3').…”