Bicyclo[2.2.2]octene‐Based Molecular Tweezers and Cyclophanes

The U‐shaped, tetraetheno‐bridged dicyclopenta[ b , i ]anthracenediol 1 was utilized as a platform molecule to construct molecular tweezers via bis‐esterification with benzoic acid and 9‐fluorenone‐2‐carboxylic acid using Yamaguchi protocol, affording the respective bis‐benzoate 3 (96%) and bis‐9‐fluorenone‐2‐carboxylate 6 in 59% yield. The latter bis‐esterification was accompanied by producing a mixed diester 7 (30%) and bis‐2,4,6‐trichlorobenzoate 8 (8%). Via bis‐ O ‐alkylation of diol 1 with ortho ‐, meta ‐, or para ‐α,α′‐dibromoxylene, the corresponding cyclophanes formed by the modes of [1+1] and [2+2] were obtained. Single‐crystal X‐ray structures of molecular tweezers 3 , 6 , 7 , [1+1]cyclophanes 11‐ m and 11‐ p , and [2+2]cyclophane 12‐ o were obtained and described.