A Divergent Diastereoselective Approach to Bicyclopropanes

The diastereoselective cyclopropanation of three stereoisomerically unique vinylcyclopropanes was studied. The selective preparation of six stereoisomeric bicyclopropanes was accomplished by an iterative reagent-controlled process. With the exception of the cis-syntrans-bicyclopropane, all isomers can be prepared in a diastereomeric excess of greater than 5:1