The Pseudotransannular Ring Opening of 1?Aminocyclohept?4?ene?derived Epoxides in the Synthesis of Tropane Alkaloids: Total Synthesis of (±)?Ferrugine

We have optimized a synthetic approach to (±)-Ferrugine in 8 steps starting from 5-aminocyclohept-1-ene and using the Brønsted acid-catalyzed pseudotransannular ring-opening of epoxide derived this cycloheptene as key step for construction 8-azabicyclo[3.2.1]octane central core. While attempting enantioselective synthesis natural product enantiopure 2-hydroxy-8-azabicyclo[3.2.1]octane we found that compound shows pronounced tendency racemize via an achiral symmetric aziridinium intermediate. This racemization side process has been studied detail both experimental computational methods.