Studies on Active Principles of Tars. X. The Structures and Some Reactions of Antifungal Constituents in Pix Pini

By following the antifungal activity, four antifungal principles, acetovanillone(1), two new cyclic β-diketones, (2 and 3), and an unknown compound (4), were isolated from wood tar, Pix Pini, which has been used traditionally for the treatment of fungal diseases in Japan. The structures of 2 and 3 were established by synthesis to be 1,1', 3,3'-tetraoxo-2,2'-bicyclopentyl and its 4-methyl derivative, respectively. Chemical reactivities and physical properties of 2 and 3 are also described.