Progress on PPAPs cyclization: Guttiferone A as a case study

Biotransformation of guttiferones, Symphonia globulifera metabolites, by Bipolaris cactivora, an endophytic fungus isolated from its leaves

“…However, xanthone (2) obtained by yeast-cyclization of guttiferone A (1) showed better activity against Plasmodium falciparum. 26 This regio-selective cyclization is interesting since we reported 27 that it is possible to obtain four xanthone-type-compounds with 3,16, 1,16, 3,12 and 1,12 pattern corresponding to compounds 2, 3, 4 and 5 (Fig. 1) respectively.…”

Me2AlSEt-Promoted Domino Dieckmann Cyclization Enables the Total Synthesis of Polycyclic Polyprenylated Acylphloroglucinols

“…The Lewis acid SmCl 3 has indeed substantially promoted the reaction not only with benzoyl chloride but also with benzoyl cyanide. Under the current set of conditions, the reactions with the cyclic sterically hindered substrates proceeded very smoothly and were complete in 2 h. The subsequent oxidative cyclization was then conducted with high regioselectivity under different oxidative conditions to give garcimultiflorone I ( 3 ) in 58% yield and regio -garcimultiflorone I ( 21 ) in 27% yield …”