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5‐Azido Derivatives of Neuraminic Acid − Synthesis and Structure
Author(s) -
Schneider Regine,
Freyhardt Clemens C.,
Schmidt Richard R.
Publication year - 2001
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200105)2001:9<1655::aid-ejoc1655>3.0.co;2-8
Subject(s) - chemistry , regioselectivity , acetylation , diazo , moiety , derivative (finance) , neuraminic acid , stereochemistry , acceptor , glycosyl donor , azide , medicinal chemistry , glycosyl , organic chemistry , catalysis , biochemistry , sialic acid , physics , financial economics , economics , gene , condensed matter physics
Benzyl sialoside 1 was transformed into the corresponding 5‐azido derivative 4 by N ‐nitrosation of the 5‐acetylamino group and treatment with base followed by hydrazoic acid or, alternatively, by N,O ‐deacetylation followed by diazo group transfer to the amino moiety by means of TfN 3 . Regioselective 4‐ O ‐acetylation and introduction of the MPM group at 9‐ O afforded glycosyl acceptor 11 . N,O ‐Deacetylation of ethyl 2‐thiosialoside 13 afforded 14 which, after diazo group transfer to the amino group, furnished 5‐azido derivative 16 , which can serve as a sialyl donor. Activation of the ethylthio leaving group in the absence of an acceptor afforded 2,3‐dehydro derivative 17 . Regioselective 4‐ O ‐acetylation and 9‐ O ‐benzylation furnished glycosyl acceptor 22 . An X‐ray analysis was obtained from crystals of the 7,8,9‐ O ‐unprotected intermediate 21 .