3,7-Dihydroxytropolones (3,7-dHTs) are highly oxygenated troponoids that have been identified as lead compounds for several human diseases. To date, structure-function studies on these molecules have been limited due to a scarcity of synthetic methods for their preparation. New synthetic strategies towards structurally novel 3,7-dHTs would be valuable in further studying their therapeutic potential. Here we describe the successful adaptation of a [5 + 2] oxidopyrilium cycloaddition/ring-opening for 3,7-dHT synthesis, which we apply in the synthesis of a plausible biosynthetic intermediate to the natural products puberulic and puberulonic acid. We have also tested these new compounds in several biological assays related to human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV) in order to gain insight into structure-functional analysis related to antiviral troponoid development.
Hirsch DR, Schiavone DV, Berkowitz AJ, Morrison LA, Masaoka T, Wilson JA, Lomonosova E, Zhao H, Patel BS, Datla SH, Hoft SG, Majidi SJ, Pal RK, Gallicchio E, Tang L, Tavis JE, Le Grice SFJ, Beutler JA, Murelli RP. Synthesis and biological assessment of 3,7-dihydroxytropolones. Organic & biomolecular chemistry 2018; 16: 62-69.