Synthesis of Calystegine A 3 from Glucose by the Use of Ring‐Closing Metathesis

Abstract A synthesis of the nortropane alkaloid calystegine A 3 is described from D ‐glucose. The key step employs a zinc‐mediated tandem reaction where a benzyl‐protected methyl 6‐iodo glucoside is fragmented to give an unsaturated aldehyde, which is then transformed into the corresponding benzylim...

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Bibliographic Details
Published inEuropean journal of organic chemistry Vol. 2009; no. 20; pp. 3387 - 3395
Main Authors Monrad, Rune Nygaard, Pipper, Charlotte Bressen, Madsen, Robert
Format Journal Article
LanguageEnglish
Published 01.07.2009
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Summary:Abstract A synthesis of the nortropane alkaloid calystegine A 3 is described from D ‐glucose. The key step employs a zinc‐mediated tandem reaction where a benzyl‐protected methyl 6‐iodo glucoside is fragmented to give an unsaturated aldehyde, which is then transformed into the corresponding benzylimine and allylated in the same pot. The functionalized nona‐1,8‐diene, thus obtained, is converted into the seven‐membered carbon skeleton in calystegine A 3 by ring‐closing olefin metathesis. Subsequent deoxygenation by the Barton–McCombie protocol, hydroboration and oxidative workup followed by hydrogenolysis affords calystegine A 3 . The synthesis uses a total of 13 steps from glucose and confirms the absolute configuration of the natural product.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
ISSN:1434-193X
1099-0690
DOI:10.1002/ejoc.200900310