title: The total synthesis of hyperpapuanone, hyperibone L, epi-clusianone and oblongifolin A.
abstract: Polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products that possess a wide range of different important biological activities because of the relative position and configuration of four substituents that decorate one common central bicyclo[3.3.1]nonane-2,4,9-trione core. The rigid bicyclic framework with its lipophilic side chains and its hydrophilic trione moiety represents a nature-derived lead structure that arranges the substituents (R(1) to R(4)) into a defined topographical orientation. As the substituents are responsible for the biological activities, the seven-step synthetic approach presented here sets the stage for an iterative introduction of R(1) to R(4) and thus generates structurally diverse trans-type B PPAPs. Four natural and one non-natural trans-type B PPAPs were prepared starting from acetylacetone with overall yields that ranged from 6 to 22%. The concept of separating framework construction from decorating transformations plus the minimization of protecting-group operations are the key issues for the realization of our synthetic approach.
authors: Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569                 Stuttgart, Germany.
authors: Nicole
authors: N
authors: Biber
authors: Katrin
authors: K
authors: Möws
authors: Bernd
authors: B
authors: Plietker
mesh_terms: D001577:Benzophenones; D016227:Benzoquinones; D001688:Biological Products / Q000138:chemical synthesis*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C118110:7-epiclusianone; D001577:Benzophenones; D016227:Benzoquinones; D001688:Biological Products; D001643:Bridged Bicyclo Compounds