comparison, a second bicyclic monomer containing this moiety has been synthesized. Addition of Vinylmagnesium Chloride to 3-Cyanocyclobutanone. Bicyclobutane syntheses in this series1J have involved the generation of a carbanion on the cyclobutane ring in a 1, 3 relationship to a leaving group. If an activating group (CN, COOCH3) were present at CI, abstraction of H+ by strong bases yielded the requisite carbanion; if none were present, ...