Cyclopentanone ring expansion leading to functionalized delta-lactams: short synthesis of simple sedum alkaloids.
Org Lett
; 9(14): 2673-6, 2007 Jul 05.
Article
em En
| MEDLINE
| ID: mdl-17564459
ABSTRACT
Monosubstituted epoxides react with (cyclopentenyloxy)trimethylsilane to afford, after subsequent oxidative fragmentation, a pair of diastereomeric 8-membered iodolactones. When these lactones are separately treated with sodium azide, followed by reduction over Lindlar's catalyst, lactone ring contraction yields 6-membered monosubstituted lactams. When (R)-1,2-epoxypentane is used in this 5 + 3 - 2 overall ring expansion sequence, one final step involving delta-lactam to piperidine reduction yields natural (-)-halosaline and (-)-epihalosaline in five steps and 12% and 23% overall yields, respectively.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Org Lett
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos