A concise total synthesis of the azaphenanthrene alkaloid eupolauramine.
J Org Chem
; 66(24): 8064-9, 2001 Nov 30.
Article
em En
| MEDLINE
| ID: mdl-11722206
ABSTRACT
A six-step total synthesis of the azaphenanthrene alkaloid eupolauramine 1 has been achieved using combinational metalation-cyclization tactics. The synthetic route involved first the construction of the azaisoindolinone 9 by aryne-mediated cyclization of he phosphorylated pyridocarboxamide 7 and subsequent dephosphorylation. Metalation of 9 followed by connection of the hydroxybenzyl appendage and E(1)CB anti-elimination allowed the formation of the halogenoarylmethylene azaisoindolinone 4 in the exclusive E-form. Oxidative radical cyclization gave rise to the azaphenanthrene skeleton and regioselective bromination of 3 induced the incorporation of the bromine atom at the 6-position of the azaphenanthrene lactam. Ultimate replacement of the bromine atom of 2 by the methoxy functionality by sequential transmetalation, in situ oxidation, and O-methylation of the phenolic derivative 14 completed the synthesis of the target natural product eupolauramine.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenantrenos
/
Compostos Aza
/
Alcaloides
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article