合成路线1

The bromination of the acetoxytropanone (I) with Br2 gives the bromo derivative (II), which is treated with Ag2CO3 to yield the hydroxy compound (III). The reaction of (III) with ethane-1,2-dithiol (IV) in acid medium affords the cyclic dithioketal (V), which is desulfurized with H2 over Raney-Ni providing the tropanol derivative (VI). The oxidation of (VI) with CrO3 gives the tropanone derivative (VII), which is stereoselectively reduced with NaBH4, yielding the tropanol compound (VIII). Finally, this compound is demethylated by reaction with 2,2,2-trichloroethyl chloroformate and reduction with Zn and acetic acid.