Total Synthesis of Marine Alkaloids Cystodytins A–K
Dongfang Jiang, Yang Chen, Shaozhong Wang
Abstract
The total synthesis of marine alkaloids cystodytins A–K has been accomplished in five to six steps starting from commercially available compounds. The highlights of the synthesis include an oxidative amination–cyclization of tryptamine and para-hydroquinones to build a tetracyclic pyridoacridinone ring with different side chains and a copper(II)-catalyzed enantioselective Henry reaction to construct an oxygenated stereogenic carbon center. For the first time, the absolute configuration of the stereogenic centers embedded in cystodytins D–I and K was established as R. Moreover, the stereochemistry of the olefin unit in the side chain of cystodytins H and I was revised to the Z configuration from the originally assigned E configuration.