The first total synthesis of (-)-Przewalskin B has been accomplished with an intramolecular nucleophilic acyl substitution (INAS) reaction and an intramolecular aldol condensation as key steps.
total synthesis of przewalskin B was accomplished from readily available diene 7. Key features of the synthesis involved a Diels–Alder reaction to install the A ring, a Claisen–Johnson rearrangement to establish the spiro-quaternary center, and a ring-closingmetathesis (RCM) of a sterically crowded system to construct the cyclic enone moiety.