Novel entry into oxepane–diquinane and oxepane–sterpurane hybrids: synthesis and photochemistry of 3-oxatricyclo[7.2.2.01,7]tridecenones

A new synthesis of 3-oxatricyclo[7.2.2.01,7]tridecenones via intramolecular π4s+π2s cycloaddition in cyclohexa-2,4-dienones is described. Their photochemical reactions leading to oxepane–diquinane and oxepane–sterpurane hybrids are depicted. The crystal structure of a key intermediate is also presented.