Two cis‐fused cyclopenteno‐1,2,4‐trioxanes, 1a and 1b, were subjected to Zn in AcOH or FeCl₂·4H₂O in MeCN. In the first case, the main course was deoxygenation to give cyclopentanone (18) and the 1,4‐diphenyl‐ or 1,4‐bis(4‐fluorophenyl)cyclopent‐3‐ene‐1,2‐diol 10 (Scheme 5). In the second case, isomerization chiefly occurred resulting in the formation of a dimer 9 of the respective 3,5‐diaryl‐5‐hydroxycyclopent‐2‐enyl 5‐hydroxypentanoates 8 (Scheme 3).