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Asymmetric Synthesis via Heterocyclic Intermediates, XLVII. Asymmetric Synthesis of (+)-(1R,2S)-allo-Coronamic Acid

✍ Scribed by Groth, Ulrich ;Halfbrodt, Wolfgang ;Schöllkopf, Ulrich

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

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✦ Synopsis

Abstract

allo‐Coronamic acid (1) was synthesized in five steps enantiomerically and diastereomerically virtually pure by starting from the bislactim ethers of cyclo(‐L‐Val‐Gly‐) (3a) or cyclo‐(‐L‐tert‐Leu‐Gly‐) (3b) in an overall yield of 31%. The key step of this synthesis is the intramolecular alkylation of the lithium azaenolate derived from the allylic chloride 4.

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