The Total Synthesis of (+)-Dragmacidin F

摘要

The dragmacidins represent a small but growing family of marine alkaloids that possess a variety of interesting structural and biological features.These novel alkaloids have attracted considerable attention from the synthetic community over the past decade.Our interest in the dragmacidins was piqued by the structurally complex,pyrazinone-containing members,dragmacidins D,E,and F (Scheme 1,1-3).We recently completed the first and,to date,only total synthesis of any of these three unique alkaloids with our preparation of (±)-dragmacidin D (I).In this communication,we detail the enantiospecific total synthesis of (+)-dragmacidin F (3),which features a palladium-mediated intramolecular oxidative carbocyclization,a halogen-selective Suzuki cross-coupling reaction,and a high-yielding late-stage Neber rearrangement.