The title compound is synthesized from the optically active lactone (I). Aluminum chloride-catalyzed aminolysis of (I) with dipropylamine affords the hydroxy amide (II). Subsequent Swern oxidation of the alcohol function of (II) leads to aldehyde (III). Addition of ethylmagnesium bromide to aldehyde (III) then stereoselectively provides the (S)-alcohol adduct (IV). Introduction of an azido group in (IV) by using a Mitsunobu-type reaction leads to configuration-retained azide (V). This is finally reduced to the desired amine by catalytic hydrogenation in the presence of Pd/C