Opening of the known lactone (I) with HBr in HOAc produces the racemic cis bromo-acid (II). Acid (II) is then converted to the corresponding methyl ester (III) by chlorination with SOCl2, followed by treatment with methanolic HCl. Acylation of 1-adamantanamine (IV) with ethyl formate yields the formamide (V), which is subsequently reduced to the N-methyl amine (VI) employing LiAlH4 in THF. Finally, alkylation of the secondary amine (VI) with bromo ester (III) in the presence of NaHCO3 in hot DMF gives rise to the title compound.

In a closely related method, bromo-ester (I) is condensed with 1-adamantanamine (II) in hot DMF to afford amino ester (III). The secondary amine of (III) is then alkylated with iodomethane to produce the title compound.