The design and synthesis of enantiomerically enriched hybrid molecules, la-e and 2a-c, have been accomplished by employing the lipase-mediated asymmetric acetylation of prochiral diol 9 as the key step. Evaluation of their DNA-cleaving activity has revealed the unnatural type of enantiomer 2a-c to be more potent than la-e with natural configuration. (C) 1997 Elsevier Science Ltd.