Stereoselective cyclopropanation of chiral 5-substituted dihydro-2H-piperazines

The Simmon-Smith cyclopropanation of enantiomerically enriched dehydropiperazines is reported. The reaction is highly stereoselective and allowed us to prepare new, enantiomerically enriched 3-substituted 2,5-diazabicyclo[4.1.0]heptane cores with high diastereomeric purity and a relative anti-configuration, which was assigned by NMR analysis