3-Aryltetronic acids: efficient preparation and use as precursors for vulpinic acids.
J Org Chem
; 74(3): 1124-9, 2009 Feb 06.
Article
em En
| MEDLINE
| ID: mdl-19102655
ABSTRACT
3-Aryltetronic acids were prepared in one step by treatment of a mixture of methyl arylacetates and methyl hydroxyacetates with potassium tert-butoxide, via tandem transesterification/Dieckmann condensation. Several mushroom or lichen pigments, vulpinic acids, were synthesized from 3-(4-methoxyphenyl)tetronic acid in three steps involving the reaction of the corresponding dianion with an alpha-ketoester and the dehydration of the tertiary alcohols obtained into mixtures of (E)- and (Z)-alkenes, which were converted under UV irradiation at 254 nm to natural (E)-isomers. Syntheses of pinastric acid, 4,4'-dimethoxyvulpinic acid, and the first synthesis of recently isolated methyl 3',5'-dichloro-4,4'-di-O-methylatromentate were hence achieved in an efficient manner.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fenilacetatos
/
Furanos
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article