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- Title
2-Azido-2-deoxycellulose: Synthesis and 1,3-Dipolar Cycloaddition.
- Authors
Fuyi Zhang; Bruno Bernet; Véronique Bonnet; Olivier Dangles; Francisco Sarabia; Andrea Vasella
- Abstract
Chitosan (1) was prepared by basic hydrolysis of chitin of an average molecular weight of 70000 Da, 1H-NMR spectra indicating almost complete deacetylation. N-Phthaloylation of 1yielded the known N-phthaloylchitosan (2), which was tritylated to provide 3aand methoxytritylated to 3b. Dephthaloylation of 3awith NH2NH2⋅H2O gave the 6-O-tritylated chitosan 4a. Similarly, 3bgave the 6-O-methoxytritylated 4b. CuSO4-Catalyzed diazo transfer to 4ayielded 95 of the azide 5a, and uncatalyzed diazo transfer to 4bgave 82 of azide 5b. Further treatment of 5awith CuSO4produced 2-azido-2-deoxycellulose (7). Demethoxytritylation of 5bin HCOOH gave 2-azido-2-deoxy-3,6-di-O-formylcellulose (6), which was deformylated to 7. The 1,3-dipolar cycloaddition of 7to a range of phenyl-, (phenyl)alkyl-, and alkyl-monosubstituted alkynes in DMSO in the presence of CuI gave the 1,2,3-triazoles 8–15in high yields.
- Subjects
CHITOSAN; HYDROLYSIS; MOLECULAR weights; RING formation (Chemistry)
- Publication
Helvetica Chimica Acta, 2008, Vol 91, Issue 4, p0
- ISSN
0018-019X
- Publication type
Article
- DOI
10.1002/hlca.200890064