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Synthesis of α-N-Ketosides ofN-Acetylneuraminic Acid by Using Phase-Transfer Catalysis

✍ Scribed by Rothermel, Jörg ;Weber, Bernd ;Faillard, Hans

Publisher
John Wiley and Sons
Year
1992
Tongue
English
Weight
514 KB
Volume
1992
Category
Article
ISSN
0947-3440

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✦ Synopsis

Abstract

α‐N‐Ketosides of N‐acetylneuraminic acid (Neu5Ac) can be synthesized by using azide and thiocyanate salt as aglycone under conditions of phase‐transfer catalysis (PTC). The catalytic hydrogenation of the 2‐α‐azido ketoside 3 leads to the 2‐α‐amino ketoside 4 in good yield. This 2‐α‐amino ketoside 4 can be transformed into the 2‐α‐acetamido ketoside 5 and the 2‐α‐benzoylamido ketoside 6. Zemplén deacetylation and saponification give the corresponding 2‐N‐acyl ketosides 7 and 8, which cannot be hydrolyzed by neuraminidase (Clostridium perfringens). Treatment of the 2‐α‐amino ketoside 4 with p‐nitrobenzaldehyde results in the formation of p‐nitrobenzylideneamine 9. Based on the strict stereoselectivity of the PTC glycosidation reaction with sialic acid derivatives and the exclusive formation of the N‐ketoside 10 in the reaction with potassium thiocyanate, a model of the mechanism of the PTC glycosidation procedure with sialic acid derivatives has been evaluated.

📜 SIMILAR VOLUMES

Phase-transfer-catalyzed synthesis of a
Phase-transfer-catalyzed synthesis of a phenylseleno α-ketoside of N-acetylneuraminic acid, (phenyl 5-acetamido-3,5-dideoxy-d-glycero-α-d-galacto-2-selenononulopyranosid)-onic acid; a new sialidase inhibitor
✍ Jörg Rothermel; Hans Faillard 📂 Article 📅 1990 🏛 Elsevier Science 🌐 English ⚖ 295 KB

Selenium-substituted carbohydrates are known but rare compounds'. In sialic acid chemistry, they are gaining an increasing interest with regard to their use in stereocontrolled glycosidation reactions. Ito and Ogawaz4 reported a phenylselenosubstituted sialic acid derivative which they used in glyc