Synthesis and oligomerization of cysteinyl nucleosides

Abstract

Nucleoside and nucleic acid analogues are known to possess a considerable therapeutic potential. In this work, by coupling cysteine to nucleosides, we successfully synthesized compounds that may not only have...

The Very First Modification of Pleuromutilin and Lefamulin by Photoinitiated Radical Addition Reactions—Synthesis and Antibacterial Studies

“…Thus, if the conversion was not satisfactory after 15 min., the reaction mixture was subjected to UV-irradiation for further 1-2 × 15 min. The thiol-ene coupling is tolerant to water and oxygen and is compatible with any solvent [24,[31][32][33]. Therefore, we performed the reactions without any caution to exclude air or moisture, and selected different solvents on the basis of the solubility of the reactants.…”

“…Recently, we have demonstrated that the reaction temperature influences the efficacy of the photoinitiated thiol-ene reactions in a unique way. Cooling promotes, whereas heating inhibits, the thiol-ene couplings [20][21][22]24,[31][32][33].…”

Synthesis of Potential Glycosyl Transferase Inhibitors by Thio‐Click Reactions

“…We have also shown, that the thiol-ene coupling reaction of C4'-exomethylene derivatives of nucleosides provides an easy route to 5'-thioconjugated derivatives. [16,17] On the basis of these results we envisioned the replacement of the pyrophosphate unit of UDP-sugars with a dithio-alkyl group by two subsequent thiol-ene coupling reactions using 1,2-ethanedithiol II as the thiol and glycals I and nucleosides III as the alkene reactants (Scheme 1B). Moreover, the thiol-ene coupling reaction was also exploited for the synthesis of morpholine ring nucleoside analogues as potential GT inhibitors via hydrothiolation of 2-substituted glycals I with thioacetic acid IV and coupling of the ensuing α-thiols to N-allyl morpholinos V (Scheme 1C).…”

“…[15,16] We have demonstrated that hydrothioylation of C4'-exomethylene derivatives of nucleosides at room temperature proceeds with low stereoselectivity, but the level of stereoselectivity can be gradually increased by decreasing the reaction temperature. [16,17] Therefore, it was crucial to conduct the hydrothiolation of 4 at À 80 °C to achieve high D-ribo selectivity. The synthesis of compound 5 was also accomplished by first coupling 1,2-ethanedithiol monoacetate to uridine 4 and then reacting the resulting 6 a, [16] after selective S-deacetylation, with the glycal derivative 1.…”

“…Next, the UDP-GlcNAc analogue 12 was prepared starting from 2-acetamido-D-glucal 9, 1,2-ethanedithiol, and the 4'exomethylene uridine 4 (Scheme 4). Hydrothiolation of glycal 9 with the 1,2-dithiol using 5 × 5 min UV irradiation cycles [12][13][14][15][16][17] at À 80 °C produced the 1,2-cis-α-thioglycoside 10 with full selectivity. At room temperature, the yield of 10 was only 52 % due to insufficient conversion.…”