Synthesis of tetra- and octahydroxanthene derivatives by the condensation of dimedone with aromatic aldehydes

Article abstract of DOI:10.1007/BF01164861

The reaction of dimedone with salicyl and 2-hydroxy-1-naphthoyl aldehydes gave derivatives of tetrahydroxanthene and tetrahydrobenzo[a]xanthene and not aldimedone as occurs in condensations with other aldehydes. Derivatives of decahydroacridine were obtained by reaction of the tetrahydroxanthene derivatives with methyl-and ethylamine. Tetrahydro- and octahydroxanthene derivatives were obtained from the reaction of acetylsalicylaldehyde with dimedone in acetic anhydride. The structures of the ketoenol forms of the products containing a β-ketoenol unit were determined by ¹H and ¹³C NMR spectroscopy, and the mechanism of their interconversion is discussed. 1997 Plenum Publishing Corporation.