Deoxygenation at the C3 position of d- and l-arabinofuranose: stereospecific access to enantiomeric cordycepose derivatives

A new synthesis of 3′‐deoxy‐3′‐fluoroadenosine, a key intermediate of cyclic dinucleotide

“…The synthesis started with the known 5-O-TBDPS-Dlyxofuranose 1,2-acetonides 14, which could be easily obtained from cheap D-arabinose according to the publication [18]. DAST reaction of 14 proceeded smoothly in the presence of pyridine to give corresponding Desilylation of 15 then took place along with simultaneous acidic methanolysis of isopropylidene group in refluxed MeOH, affording methyl-3-deoxy-3-fluoro-D-arabinofuranoside 16 in good yield.…”

“…The synthesis started with the known 5‐ O ‐TBDPS‐D‐lyxofuranose 1,2‐acetonides 14 , which could be easily obtained from cheap D‐arabinose according to the publication [18]. DAST reaction of 14 proceeded smoothly in the presence of pyridine to give corresponding 3‐deoxy‐3‐fluoro‐D‐arabinofuranose 1,2‐acetonides 15 .…”

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

“…Phenylthionocarbonates (v, Fig. 4) have also been extensively used, 116–123 as well as cyclic phenylthionocarbonates (vi, Fig. 4), which have been used, for example, for the synthesis of pentopyranosyl nucleoside phosphonates (Scheme 22A) 90 and (+)-muscarine (Scheme 22B).…”

Rules and Stereoelectronic Guidelines for the Anionic Nucleophilic Displacement of Furanoside and Furanose O-Sulfonates

“…(c) α­(1,2,3)-β(4)-1,2-O-Isopropylidene-O3-sulfonates (eq ) ,− ,− and their α­(1,2,3,4)-1,2-O-isopropylidene-O3-sulfonate counterparts (eq 17) ,− both readily engage in S N 2 displacements with charged nucleophiles, but elimination is sometimes problematical for the latter type of substrate, particularly when the nucleophile has significant basicity. This is due to H(4) being anti with respect to the C(3)–OSO 2 R group and the latter acidifying these H atoms by electron withdrawal. …”