A high yielding chemical synthesis of sialyl Lewis x tetrasaccharide and Lewis x trisaccharide; examples of regio- and stereodifferentiated glycosylations
(1998) In Journal of Organic Chemistry 63(25). p.9314-9322- Abstract
Virtually complete regioselective galactosylation of the diol acceptor p-methoxyphenyl 6-O-benzyl-2-deoxy-2-tetrachlorophthalimido-β-D- glucopyranoside (8) with the donor phenyl 2,3,4-tri-O-acetyl-6-O-benzyl-1- thio-β-D-galactopyranoside (11) gave the lactosamine derivative 14, which was fucosylated with the donor 15 to give the Le(x) trisaccharide glycoside 2 after deprotection. Regioselective sialylation of the partially protected Le(x) trisaccharide triol 24 with the sialyl donor 25 gave, after deprotection, the SLe(x) tetrasaccharide glycoside 1. The overall yields of 2 and 1 from the monosaccharide starting materials 8, 11, 15, and 25 were 56% and 29%, respectively. In contrast to the virtually complete regio- and stereoselective... (More)
Virtually complete regioselective galactosylation of the diol acceptor p-methoxyphenyl 6-O-benzyl-2-deoxy-2-tetrachlorophthalimido-β-D- glucopyranoside (8) with the donor phenyl 2,3,4-tri-O-acetyl-6-O-benzyl-1- thio-β-D-galactopyranoside (11) gave the lactosamine derivative 14, which was fucosylated with the donor 15 to give the Le(x) trisaccharide glycoside 2 after deprotection. Regioselective sialylation of the partially protected Le(x) trisaccharide triol 24 with the sialyl donor 25 gave, after deprotection, the SLe(x) tetrasaccharide glycoside 1. The overall yields of 2 and 1 from the monosaccharide starting materials 8, 11, 15, and 25 were 56% and 29%, respectively. In contrast to the virtually complete regio- and stereoselective galactosylation of 8, fucosylation with the benzyl-protected donor 15 gave the corresponding 1→3- and 1→4-linked disaccharides in a ratio of 3.6:1 (highly stereo- but not regioselective glycosylation), whereas fucosylation with acetyl-protected donor 18 gave a 2.2:1 β/α-mixture of 4- O-linked disaccharides (highly regio- but not stereoselective glycosylation).
(Less)
- author
- Ellervik, Ulf LU and Magnusson, Göran LU
- organization
- publishing date
- 1998-12-11
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Organic Chemistry
- volume
- 63
- issue
- 25
- pages
- 9 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:0032509249
- ISSN
- 0022-3263
- DOI
- 10.1021/jo981203x
- language
- English
- LU publication?
- yes
- id
- 3c7e5f46-4b5f-484d-8290-623b4bc70dd8
- date added to LUP
- 2023-08-11 08:12:52
- date last changed
- 2023-08-15 09:24:22
@article{3c7e5f46-4b5f-484d-8290-623b4bc70dd8,
abstract = {{<p>Virtually complete regioselective galactosylation of the diol acceptor p-methoxyphenyl 6-O-benzyl-2-deoxy-2-tetrachlorophthalimido-β-D- glucopyranoside (8) with the donor phenyl 2,3,4-tri-O-acetyl-6-O-benzyl-1- thio-β-D-galactopyranoside (11) gave the lactosamine derivative 14, which was fucosylated with the donor 15 to give the Le(x) trisaccharide glycoside 2 after deprotection. Regioselective sialylation of the partially protected Le(x) trisaccharide triol 24 with the sialyl donor 25 gave, after deprotection, the SLe(x) tetrasaccharide glycoside 1. The overall yields of 2 and 1 from the monosaccharide starting materials 8, 11, 15, and 25 were 56% and 29%, respectively. In contrast to the virtually complete regio- and stereoselective galactosylation of 8, fucosylation with the benzyl-protected donor 15 gave the corresponding 1→3- and 1→4-linked disaccharides in a ratio of 3.6:1 (highly stereo- but not regioselective glycosylation), whereas fucosylation with acetyl-protected donor 18 gave a 2.2:1 β/α-mixture of 4- O-linked disaccharides (highly regio- but not stereoselective glycosylation).</p>}},
author = {{Ellervik, Ulf and Magnusson, Göran}},
issn = {{0022-3263}},
language = {{eng}},
month = {{12}},
number = {{25}},
pages = {{9314--9322}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Journal of Organic Chemistry}},
title = {{A high yielding chemical synthesis of sialyl Lewis x tetrasaccharide and Lewis x trisaccharide; examples of regio- and stereodifferentiated glycosylations}},
url = {{http://dx.doi.org/10.1021/jo981203x}},
doi = {{10.1021/jo981203x}},
volume = {{63}},
year = {{1998}},
}