Synthesis 2010(16): 2776-2786  
DOI: 10.1055/s-0030-1258140
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Total Synthesis of 3′,3′′′-Binaringenin and Related Biflavonoids

Gabriel Sagreraa, Gustavo Seoane*b
a Departamento de Química Orgánica, Facultad de Ciencias, Universidad de la República, C.C.1157, Montevideo, Uruguay
b Departamento de Química Orgánica, Facultad de Química, Universidad de la República, C.C.1157, Montevideo, Uruguay
Fax: +598(2)9241906; e-Mail: gseoane@fq.edu.uy;
Further Information

Publication History

Received 18 December 2009
Publication Date:
30 June 2010 (online)

Abstract

The synthesis of natural 3′,3′′′-binaringenin and four related biflavonoids was performed in good overall yield (15-35%) starting from readily available phloroglucinol and 4-hydroxy- or 4-methoxybenzaldehyde. Preliminary results indicate that some of these compounds have an interesting activity against S. aureus.

48

Treatment of the hexamethyl ether with 6 to 8 equiv of BBr3 in CH2Cl2 at low temperature always resulted in partial deprotection and further decomposition.

54

Treatment with BBr3 (2 equiv) in CH2Cl2 at different temperatures gives no reaction or else ring opening to the chalcone 20; the treatment with 57% HI in glacial AcOH at reflux gives mixtures of chalcone, flavanone, and dihydrochalcone in low yields, and the use of AlCl3 in benzene at reflux resulted in decomposition.