合成路线1

Demethylation of tropinone (I) by means of 1-chloroethyl chloroformate, followed by protection of the resultant secondary amine (II) with di-tert-butyl dicarbonate, leads to the N-Boc derivative (III). Treatment of the potassium enolate of (III) with N-phenyl trifluoromethanesulfonimide produces the vinyl triflate (IV), which is then converted to the stannyl derivative (V) upon treatment with hexamethylditin and palladium catalyst. Stille coupling of (V) with ethyl 2-bromobenzoate (VI) affords (VII). After catalytic double bond hydrogenation of (VII), the resultant mixture of diastereoisomers is separated by recrystallization from hexane/ethyl acetate to give (VIII). The N-Boc protecting group of (VIII) is cleaved with HCl in dioxane to yield amine (IX), which is then coupled with N-Boc-D-benzylalanine (X) to furnish amide (XI). Subsequent acidic Boc-group cleavage gives rise to the amine (XII).