Glycosyl Imidates, 74. Synthesis of Ganglioside GM 1 via a GM 3 Intermediate
1996; Wiley; Volume: 1996; Issue: 5 Linguagem: Inglês
10.1002/jlac.199619960504
ISSN0947-3440
AutoresUlrike Greilich, Roberto Brescello, Karl‐Heinz Jung, Richard R. Schmidt,
Tópico(s)Proteoglycans and glycosaminoglycans research
ResumoAbstract The synthesis of GM 1 ( 1 ) via GM 3 intermediate 7 was based on lactose building‐block 5 , sialyl donors 6 , and a Galß(1–3)‐GalN 3 donor 13α . Reaction of donor 13α with acceptor 7 in the presence of TMSOTf as catalyst afforded GM 1 pentasaccharide 30 . Azido group reduction, N ‐acetylation, hydrogenolytic O ‐debenzylation, and O ‐acetylation furnished O ‐acyl‐protected GM 1 pentasaccharide 34 . Chemoselective 1a‐ O ‐deacetylation and generation of O ‐(pentaosyl)trichloro‐acetimidate 36 provided the required glycosyl donor for the application to azidosphingosine glycosylation procedure affording GM 1 ( 1 ).
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