Progress toward the Total Synthesis of Cassaine via the Transannular Diels-Alder Strategy

摘要

The transannular Diels-Alder reaction of trans-trans-trans macrocyclic triene A, bearing two cis substiuents in C_(12) and C_(13) as well as a gem-dimethyl in C_4, was studied. Under thermal conditions, only the desired trans-anti-cis tricycle B was obtained. This tricycle represents an advanced intermediate toward the total synthesis of cassaine C.