Rh^I‐Catalyzed [6+2] Cycloaddition of Alkyne–Allenylcyclobutanes: A New Entry for the Synthesis of Bicyclo[6.m.0] Skeletons

Abstract

Bicyclo under construction! The [RhCl(dppp)2]-catalyzed intramolecular [6+2] cycloisomerization of alkyne–allenylcyclobutanes efficiently produced bicyclo[6.4.0]dodecatriene and bicyclo[6.3.0]undecatriene skeletons (see scheme). Straightforward cleavage of the unfunctionalized simple cyclobutane and construction of the bicyclo[6.m.0] frameworks could be achieved under mild conditions.