3-Aryltetronic acids: efficient preparation and use as precursors for vulpinic acids.
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.
Mallinger
Aurélie
A
CEA, iBiTecS, Service de Chimie Bioorganique et de Marquage, Bat. 547, 91191 Gif-sur-Yvette, France.
Le Gall
Thierry
T
Mioskowski
Charles
C
D000085:Acetates / Q000737:chemistry; D000440:Butanols / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D010648:Phenylacetates / Q000138:chemical synthesis* / Q000737:chemistry
D000085:Acetates; D000440:Butanols; D005663:Furans; D010648:Phenylacetates; C077134:vulpinic acid; C077664:tert-butoxide, potassium; C003422:tetronic acid