An efficient short-step total synthesis of ganglioside GM3: effective usage of the neighbouring group participation strategy
✍ Scribed by Toshiyuki Tomoo; Tadao Kondo; Hiroyuki Abe; Syunji Tsukamoto; Minoru Isobe; Toshio Goto
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 953 KB
- Volume
- 284
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
We have developed an efficient methodology for highly stereoselective sialylation using 3-position substituted sialic acids and have prepared 2a having a 3fl-phenylthio group as a sialic donor. Glycosylation of suitably protected lactoside 3 with 2a gave only the a-sialyl trisaccharide 16 in good yield. Condensation of the azidosphingosine 4 with the acetate 17 using promotors, DMTST or NIS-TfOH, afforded the glycolipid 18, which was directly transformed to 20 by reduction with Bu3P and subsequent acylation with octadecanoic acid in the presence of WSC. Removal of the protecting groups generated ganglioside GM 3 (1). © (1996) Elsevier Science Ltd.