The Synthesis and Chemistry of 1,3‐Bridged Polycyclic Cyclopropenes: 8‐Oxatricyclo[3.2.1.02,4]octa‐2,6‐dienes

Three 1,3‐bridged polycyclic cyclopropenes, exo‐8‐oxatricyclo3.2.1.0^2,4]octa‐2,6‐diene ( 10 ), endo‐8‐oxatricyclo3.2.1.0^2,4]octa‐2,6‐diene ( 11 ), and exo‐6,7‐benzo‐1,5‐diphenyl‐8‐oxatricyclo3.2.1.0^2,4]octa‐2,6‐diene ( 12 ), have been synthesized by elimination of 2‐chloro‐3‐trimethylsilyl‐8‐oxatricyclo3.2.1.0^2,4]‐oct‐6‐enes, 17 , 18 and 30 , which were generated from 1‐chloro‐3‐trimethylsilylcyclopropene with furan and diphenylisobenzofuran. We have demonstrated a facile route to synthesize the highly strained 1,3‐fused polycyclic cyclopropenes, 10 , 11 , and 12 . The stereochemistry of the Diels‐Alder reactions of cyclopropene 16 with furan and DPIBF are different. Cyclopropene 16 was treated with furan to form exo‐exo and endo‐exo adducts (5:2) and treated with DPIBF to generate an exo‐exo adduct. Compounds 10 , 11 and 12 undergo isomerization reactions to form benzaldehyde and phenyl 4‐phenyl‐1]naphthyl ketone to release strain energies via diradical mechanisms.