Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• gave 11 in good yield. Likewise, 6-O-benzyl derivative 12 was prepared to reduce reaction steps and to ensure a clean progress of the benzyl protecting group removal by catalytic hydrogenation (Scheme 2). The direct thioglycosylation of 11 with ethanethiol in the presence of BF3∙OEt2 afforded 2-thio-ᴅ

• -tagatofuranoside 13 in satisfactory yield (Scheme 3). In the course of the thioglycosylation, only the α-anomer of 13 was detected and isolated as the product. In general, the formation of α-anomers during the thioglycosylation of di-O-isopropylidene-ᴅ-tagatofuranoses 11 and 12 was controlled by the approach of a

• of 16. On the other hand, direct catalytic hydrogenation of 15 furnished target structure 3a with the hydroxy groups protected on C3 and C4 as an acetonide. Direct thioglycosylation of diacetonide 12 with corresponding thiols (PhSH, iPrSH) led to expected 2-thio-ᴅ-tagatofuranosides 17a and 17b in 44

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• ]. Some of them have been obtained by coupling protected glycosyl thiolates and n-alkyl halides [14][15][16]. Moreover, mechanochemical thioglycosylation of glycosyl acetates was used for the synthesis of n-alkyl 1-thio-α--glycosides as carbohydrate mesogens [17]. Unfortunately, the preparation of alkyl

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• appropriate reagents for a Mitsunobu thioglycosylation. However, a competitive redox reaction with the PR3-azodicarboxylate reagent system precludes this application [79][80]. In spite of that, thioglycosides 111–113 could be prepared via a Mitsunobu-type condensation of thioglycosides such as 108 and 109

TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• -deoxythioglucosides [50]. In the literature, to synthesize 2-deoxythioglycosides, a highly toxic tin hydride reagent was used to produce S-2-deoxysugars from glycosyl bromide through an anomeric glycosyl radical and acetate rearrangement, followed by subsequent thioglycosylation to afford 2-deoxythioglycosides as

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• computational methods. After the attempted thioglycosylation of 11 with EtSH in the presence of BF3·OEt2, 2-methyloxazoline derivatives 13 and 14 were isolated. Keywords: glycosyltransferases; inhibitors; D-psicofuranose; synthesis; thioglycosylation; Introduction Glycosyltransferases (GTs) belong to a family

• transformation of D-mannose, is described. In addition, the thioglycosylation of fully protected 3-acetamido-3-deoxy-D-psicofuranose 11 with ethanethiol was examined under various conditions. Results and Discussion The synthesis of the saccharide moiety of potential GnTs inhibitors started from commercially

• -psicofuranose (11) as the suitable substrate for thioglycosylation. Attempts to determine the configuration at the anomeric center in compounds 10 or 11 by employing NOE NMR technique were ambiguous. Although both derivatives 10 and 11 were crystalline solids, it was not possible to obtain suitable crystals for

Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica

• Lu Zou,
• Ruixiang Blake Zheng and
• Todd L. Lowary

Beilstein J. Org. Chem. 2012, 8, 1219–1226, doi:10.3762/bjoc.8.136

• -benzylidene-α-D-mannopyranoside (19) [26] was first methylated giving 20 and then converted into glycosyl acetate 21 in 49% yield over the two steps. Subsequent thioglycosylation provided a 52% yield of 22. The protected dibenzyl phosphate 23 was next formed by the NIS–AgOTf promoted glycosylation of dibenzyl

• . Acetolysis conditions were used to replace the methyl group at the anomeric center in 38 with an acetyl group, resulting in a 96% yield of 39. Thioglycosylation, followed by coupling of the resulting thioglycoside donor 40 (obtained in 75% yield) with dibenzyl phosphate, gave phosphate 41 in a yield of 67

• 6-deoxy glycosyl acetate derivative 43 in 72% yield. The subsequent thioglycosylation, phosphorylation and deprotection steps proceeded, as outlined above, to give the 6-deoxy Manp-1P 13 in 43% yield over four steps. Evaluation of 9–13 as substrates for GDP-Man pyrophosphorylase With 9–13 in hand

Study of thioglycosylation in ionic liquids

• Jianguo Zhang and
• Arthur Ragauskas

Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12

• thioglycosylation protocol. Optimization studies indicated that a two fold molar equivalent amount of methyl triflate was required for these glycosidations to occur efficiently. Lesser amounts of methyl triflate resulted in decreased yields. For the reaction solvent, we chose 1-butyl-3-methylimidazolium

• -butyl-3-methylimidazolium hexafluorophosphate and 1-butyl-3-methylimidazolium methyl sulfate were also explored as glycosidation solvents, under the same reaction conditions. These thioglycosylation reactions in these solvents were found to be either unsuccessful or provided significantly reduced

• product yields. A more hydrophobic ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluormethylsulfonyl)imide was applied for the thioglycosylation of several substrates, and the experimental data indicated that there was little reaction, indicating that 1-butyl-1-methylpyrrolidinium bis