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Enantioselective Synthesis of the Originally Proposed Usneoidone Structure: Evidence for a Structural Revision
Author(s) -
Danet Michèle,
NormandBayle Marie,
Mahuteau Jacqueline,
d'Angelo Jean,
Morgant Georges,
Desmaële Didier
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300767
Subject(s) - enantioselective synthesis , chemistry , moiety , stereochemistry , pyran , alkylation , cyanohydrin , ring (chemistry) , michael reaction , organic chemistry , catalysis
The enantioselective synthesis of the initially proposed structure of usneoidone has been completed according to a convergent strategy in which the key steps were an enantioselective Michael addition involving chiral imines to set up the C12 quaternary center, and the final assembly of the chiral pyran moiety with the aromatic subunit through a cyanohydrin anion alkylation step. The obtained product displays spectroscopic data that significantly differ from the reported values. A putative revised structure in which the pyran ring is opened is proposed for usneoidones. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)