The synthesis of baogongteng A has been published: The alkylation of 3-hydroxypyridine (I) with benzylbromide (II) gives 1-benzyl-3-hydropyridinium bromide (III), which is condensed with acrylonitrile (IV) by means of triethylamine at reflux temperature, yielding the bicyclic nitrile (V). The reduction of (V) with LiAlH4 gives the bicyclic hydroxy nitrile (VII), also obtained by stepwise reduction of (V) with H2 over Pd/C to (VI) and posterior reduction to (VII) with NaBH4. The protection of (VII) with trimethylsilyl chloride and triethylamine affords the silyloxy derivative (VIII), which is treated with methylmagnesium iodide to yield the acetyl derivative (IX). Oxidation of (IX) with m-chloroperbenzoic acid (MCPBA) in CHCl3 affords the acetoxy compound (X), which is finally debenzylated by hydrogenation with H2 and Pd/C in ethanol to give the free base (XI). This is then treated with benzoic acid.

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.