Linked Life Data

15176833

Source:http://linkedlifedata.com/resource/pubmed/id/15176833

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2004-6-4
pubmed:abstractText
The glucosamine residues in heparin-like glycosaminoglycans have been found to exist as amines, acetamides, and N-sulfonates. To develop a completely general, modular synthesis of heparin, three degrees of orthogonal nitrogen protection are required. Reported herein is a strategy for the synthesis of fully N-differentiated heparin oligosaccharides in the context of target octasaccharide 1, which contains an N-acetate, N-sulfonates, and a free amine. The protecting group scheme used in the synthesis blocked the N-acetate as a N-diacetate, the N-sulfonates as azido groups, and the amine as a N-CBz; free hydroxyls were masked as benzyl ethers and O-sulfonates as acetate esters. Disaccharide and tetrasaccharide modules were synthesized using this strategy; however, the union of tetrasaccharide trichloroacetimidate 4 with disaccharide acceptor 5 unexpectedly formed the undesired beta-linked glycoside in addition to the alpha-linkage anticipated for iduronic acid nucleophiles, resulting in an inseparable 6:1 alpha/beta mixture of products. Detailed studies into the basis for this unexpected result were conducted and are also reported.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3263
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4081-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
A stereochemical surprise at the late stage of the synthesis of fully N-differentiated heparin oligosaccharides containing amino, acetamido, and N-sulfonate groups.
pubmed:affiliation
Massachusetts Institute of Technology, 77 Massachusetts Avenue 18-292, Cambridge, Massachusetts 02139, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't