An improved chemoenzymatic protocol for the synthesis of both enantiomers of trans-cyclopentane-1,2-diamine is described. The key part of the strategy relies on the synthesis and subsequent enzymatic resolution of its racemic precursor trans- N, N-diallylcyclopentane-1,2-diamine in which the primary amino group is masked as a tertiary diallylamine. Lipase B from Candida antarctica (CAL-B) catalyzes the N-acylation of this diamine with excellent enantioselectivity ( E >200). Further deallylation and derivatization of the enantioenriched compounds (ee ⩾ 97%) obtained in the biotransformation gave access to diversely substituted derivatives.