We report the synthesis of diaminocyclitol, protected 1,4-trans-1,5-cis-4,5-diamino-2-cyclopenten-1-ol. The key strategy was stereoselective vinylation of an acyclic chiral α-amino aldimine to construct syn-diamine moiety. The 1,5-cis-amino alcohol moiety was established by stereoselective reduction, and the cyclopentene structure was secured through a ring-closing metathesis reaction.