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Straightforward Synthesis of ( R )‐(−)‐Kjellmanianone
Author(s) -
Christoffers Jens,
Werner Thomas,
Frey Wolfgang,
Baro Angelika
Publication year - 2004
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200305486
Subject(s) - enantiopure drug , decarboxylation , saponification , hydroxylation , chemistry , cerium , halogenation , enantiomer , derivative (finance) , organic chemistry , enantioselective synthesis , resolution (logic) , stereochemistry , catalysis , enzyme , artificial intelligence , computer science , financial economics , economics
A direct route to enantiomerically pure (−)‐kjellmanianone is reported. The synthesis involves a cerium‐catalyzed α‐hydroxylation and an enzyme‐catalyzed procedure to resolve tertiary alcohols at key stages. The intermediate β‐oxo ester was α‐hydroxylated to give good yields of racemic kjellmanianone. The resolution of the racemic material was achieved by enzymatic saponification, followed by a chemical decarboxylation sequence to give enantiopure (−)‐kjellmanianone with 99 % ee. Bromination then afforded the (−)‐bromo derivative, whose X‐ray structure provided evidence for the R configuration of (−)‐kjellmanianone.