Stereoselective synthesis of pyridinones: application to the synthesis of (-)-barrenazines.
[reaction: see text] The stereoselective synthesis of pyridinones was accomplished by the nucleophilic addition of Grignard reagents to a chiral pyridinium salt derived from 4-methoxypyridine. This methodology was applied to an expedient synthesis of (-)-barrenazine A and B. After N-functionalization and 1,4-reduction of the pyridinone system, the corresponding alpha-amino piperidinones readily undergo dimerization to give the hexahydrodipyridinopyrazine skeleton of the barrenazine alkaloids.
Focken
Thilo
T
Department of Chemistry, Université de Montréal, Station Downtown, Quebec, Canada.
Charette
André B
AB
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011726:Pyridinium Compounds / Q000737:chemistry; D011728:Pyridones / Q000138:chemical synthesis*; D013237:Stereoisomerism; D014561:Urochordata / Q000737:chemistry
D000470:Alkaloids; D006575:Heterocyclic Compounds, 3-Ring; D011726:Pyridinium Compounds; D011728:Pyridones; C518944:barrenazine A; C518943:barrenazine B