Derivatives of bicyclobutane and bicyclo[2.1.0]pentane. Establishment of the structures of 3- and 4-tert-butyltricyclo[4.1.0.02,7yheptane and 5- and exo-4-tert-butyltricyclo[3.2.0.02,7]heptane
Stereospecific intramolecular insertion of the cyclopropylidenes produced in the reaction of cis- and trans-3-tert-butyl-7,7-dibromobicyclo[4.1.0]heptane with methyllithium