Synthèses, structure et réactivité vis-à-vis de nucléophiles du 1,2:3,4-disulfite de β-l-arabinopyranose

First Synthesis and Evaluation of the Inhibitory Effects of Aza Analogues of TSAO on HIV-1 Replication

“…In addition, the R Nglycosylated epimer 8ar was obtained as the minor compound (13.5%) starting from the 5-O-benzoylated compound 6a. The formation of R-substituted compounds via cyclic sulfites have been described in the literature 10 and their formation was found to be dependent upon the reaction temperature. In our case, several and various experimental conditions seemed to correlate this formation with the endo/exo ratio resulting in the cyclic sulfite synthesis.…”

Access to Antigens Related to Anthrose Using Pivotal Cyclic Sulfite/Sulfate Intermediates

“…On the other hand, Guiller et al reported the preparation of some methyl 4-azido-α- d -arabinopyranosides from their corresponding 3,4-cyclic sulfites in high yields and complete regioselectivity . However, when the same authors iterated the reaction on a (α- l -arabinopyranosyl)uracil derivative, the 3′-azido compound was the sole isolated product, in 50% yield, from a complex mixture in which they tentatively identified the presence of the 4′-azido regioisomer . From these extremely limited results, we envisioned that the anomeric substituent plays an important role in controlling the nucleophilic attack either at the C-3 or C-4 site and that existing 1,3-diaxial interactions will strongly disfavor attack at the former site …”

Nucleic acid related compounds. 66. Improved syntheses of 5′-chloro-5′-deoxy- and 5′-S-aryl(or alkyl)-5′-thionucleosides

“…It has been established that the 'H N M R frequencies of geminal protons on 5-membered cyclic sulfite ester rings (1,3,2-dioxathiolan-2-oxides) are shifted downfield when proximal to the exocyclic oxygen atom and upfield when distal (9,(15)(16)(17). Known correlations for cyclic sulfite 13c N M R shifts (9, 16) also were in harmony with our observed 'H and 13c N M R spectra (Tables 1 and 2).…”