N-Glycosyl Amides: Removal of the Anomeric Protecting Group and Conversion into Glycosyl Donors.

ChemInform ◽  
2003 ◽  
Vol 34 (44) ◽  
Author(s):  
Norbert Pleuss ◽  
Horst Kunz
2020 ◽  
Vol 85 (24) ◽  
pp. 16166-16181
Author(s):  
Nahoko Yagami ◽  
Amol M. Vibhute ◽  
Hide-Nori Tanaka ◽  
Naoko Komura ◽  
Akihiro Imamura ◽  
...  

2015 ◽  
Vol 44 (6) ◽  
pp. 846-848 ◽  
Author(s):  
Tomonari Tanaka ◽  
Naoya Kikuta ◽  
Yoshiharu Kimura ◽  
Shin-ichiro Shoda

1998 ◽  
Vol 63 (4) ◽  
pp. 577-589 ◽  
Author(s):  
Miroslav Ledvina ◽  
Daniel Zyka ◽  
Jan Ježek ◽  
Tomáš Trnka ◽  
David Šaman

Ethyl 3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (5), prepared by benzylation of ethyl 2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (4), was transformed by reaction with bromine into 3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl bromide (6). Thioglycoside 5 in the presence of methyl triflate and glycosylbromide 6 in the presence of silver triflate were used as glycosyl donors for condensation with benzyl 2-acetamido-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranoside (7), to give benzyl 2-acetamido-3-O-allyl-6-O-benzyl-4-O-(3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl)-2-deoxy-α-D-glucopyranoside (8). Its reductive dephthaloylation with NaBH4/AcOH afforded benzyl 2-acetamido-3-O-allyl-4-O-(2-amino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)- 6-O-benzyl-2-deoxy-α-D-glucopyranoside (11). Compound 11 was N-acylated to give benzyl 2-acetamido-4-O-(2-acylamino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranosides (12a) or (12b). These compounds were converted into corresponding benzyl 2-acetamido-4-O-(2-acylamino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-6-O-benzyl-3-O-carboxymethyl-2-deoxy-α-D-glucopyranosides which, by condensation with H-L-Abu-D-isoGln(OBzl) followed by hydrogenolysis of protective benzyl groups, furnished glycopeptides 16a and 16b. Intramolecular O→N migration of the allyl protecting group followed by its reduction to the propyl residue by reaction of compound 8 with hydrazine or hydrazinium acetate, to give benzyl 2-acetamido-4-O-(3,4,6-tri-O-benzyl-2-deoxy-2-propylamino-β-D-glucopyranosyl)-6-O-benzyl-2-deoxy-α-D-glucopyranoside (9), is also described.


2002 ◽  
Vol 55 (2) ◽  
pp. 113 ◽  
Author(s):  
W. R. Roush ◽  
N. A. Powell ◽  
R. A. James

Syntheses of aureolic acid analogues (5) and (6) with (2S)- and (2R)-acyloin stereochemistry, respectively, are described. The synthesis of (5) utilizes a `C + DE' glycosidation sequence, whereas analogue (6), with unnatural (2R)-acyloin stereochemistry, was synthesized by a sequence in which the entire C-D-E trisaccharide was introduced in a single step. While these syntheses provided sufficient quantities of the two aureolic acid analogues for use in studies of Mg2+ complex formation and deoxyribonucleic acid (DNA) binding, this work also highlights certain limitations in the use of 2-thiophenyl glycosyl donors for synthesis of 2-deoxy-β-glycosides. Specifically, difficulties were encountered in the identification of a protecting group for the aglycone C8 phenol that is fully compatible with the conditions required for reductive removal of the thiophenyl substituents after completion of the glycosidation sequence. Sensitivity of the C2 acyloin stereocentre to the conditions required for deprotection of a phenolic acetate ester are also highlighted in the syntheses of (5), and especially of (6).


2016 ◽  
Vol 2016 (8) ◽  
pp. 1520-1532 ◽  
Author(s):  
Andrew J. A. Watson ◽  
Stewart R. Alexander ◽  
Daniel J. Cox ◽  
Antony J. Fairbanks

ChemInform ◽  
2010 ◽  
Vol 33 (19) ◽  
pp. no-no
Author(s):  
Nicholas M. Kelly ◽  
Knud J. Jensen

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105589-105606 ◽  
Author(s):  
Mana Mohan Mukherjee ◽  
Nabamita Basu ◽  
Rina Ghosh

FeCl3 modulated excellent 1,2-trans selective glycosylations based on trichloroacetimidate glycosyl donors even in the presence of apparently silent C-2 protecting group, along with orthogonal glycosylation reactions are reported.


Sign in / Sign up

Export Citation Format

Share Document