Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• migration and/or elimination of the secondary acyl chain. TfOH-mediated 1,2-trans glycosylation smoothly provided β(1→6)-linked diglucosamine, the free OH group in position 3 was protected as Alloc carbonate and the benzylidene acetal protecting group was regioselectively reductively opened to furnish 6’-O

1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides

• Fei-Fei Xu,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2017, 13, 1994–1998, doi:10.3762/bjoc.13.195

• . Optimization of glycosylation conditions using DBDMH as promoter. 1,2-Trans-glycosylation activated by DBDMH with a variety of building blocks. 1,2-Cis-glycosylation activated by DBDMH. Supporting Information Supporting Information File 348: Experimental details and full characterization data of all new

A selective and mild glycosylation method of natural phenolic alcohols

• Mária Mastihubová and
• Monika Poláková

Beilstein J. Org. Chem. 2016, 12, 524–530, doi:10.3762/bjoc.12.51

• to the stereoselective glycoside synthesis. The final products were obtained by conventional Zemplén deacetylation. Keywords: diastereoselectivity; p-hydroxyphenylalkyl glycosides; mild promoters; natural products; 1,2-trans-glycosylation; Introduction Arylalkyl (substituted benzyl, phenethyl and

• participation is usually exploited in the trans-O-glycosylation of appropriate aglycones. In the course of our synthetic studies, 1,2-trans-glycosylation reactions utilizing per-O-acetyl-D-glucopyranose as a donor were initially investigated. However, the reaction of 6b with per-O-acetylated-D-glucopyranose

• order to identify the optimal glycosylation conditions in terms of yield and selectivity. In all cases, only the 1,2-trans-glycosylation product, β-glucoside 21b, was obtained. While method B (ZnO–ZnCl2) performed in DCM instead of ACN afforded only a moderate yield (Table 1, entry 2, 46%) of 21b, the

Convergent synthesis of a tetrasaccharide repeating unit of the O-specific polysaccharide from the cell wall lipopolysaccharide of Azospirillum brasilense strain Sp7

• Pintu Kumar Mandal,
• Debashis Dhara and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2014, 10, 293–299, doi:10.3762/bjoc.10.26

• (signals at δ 5.50 (d, J = 10.0 Hz, H-1c), 4.97 (d, J = 3.5 Hz, H-1D), in the 1H NMR and δ 100.5 (C-1D), 80.6 (C-1C) in the 13C NMR spectra). Finally, the 1,2-trans-glycosylation of compound 8 with the thioglycoside donor 9 in the presence of NIS–TfOH [39][40] furnished tetrasaccharide derivative 10 in 72