The first reported anionic oxy retro-ene reaction.

Treatment of the diol 6 with KH and 18-C-6 at room temperature gives the cyclopentenone 7 in good yields. Mechanistic analysis reveals that this is the first case of an anionic oxy retro-ene reaction followed by a tandem intramolecular aldol condensation. Reaction: see text.

Conclusive evidence of the trapping of primary ozonides.

[reaction: see text] Anomalous ozonolysis of strained bicyclic allylic alcohols yields alpha-hydroxymethyl ketones. The proposed mechanism involves an unusual trapping of the primary ozonide that undergoes a Grob-like fragmentation instead of dissociating into the Criegee intermediates.