Bioinspired synthesis of pentacyclic onocerane triterpenoids. Issue 12 (23rd October 2017) - Bartels, Florian
Abstract : The first chemical synthesis of pentacyclic onocerane triterpenoids (+)-cupacinoxepin and (+)-onoceranoxide is described. Abstract : The first chemical synthesis of pentacyclic onocerane triterpenoids has been achieved. A putative biomimetic tricyclization cascade is employed to forge a fused decalin-/oxepane ring system. The synthetic route proceeds to (+)-cupacinoxepin in seven steps and to (+)-onoceranoxide in eight steps in the longest linear sequence, when starting from geranyl chloride and (+)-sclareolide. The bioinspired epoxypolyene cyclization is supported by computational and enzymatic studies.