Beschreibung:
AbstractReaction of title compound 1 with dichloroketene resulted in a complex rearrangement to 2 when the ketene was generated from Cl3CCOCl/Zn. In contrast, treatment of 1 with the ketene produced from dichloroacetyl chloride/triethylamine gave a bicyclo[3.2.0]heptenone (3) along with acylation product 4. Reaction of monochloroketene with 1 afforded the „normal”︁ endo‐chloro compound 6 which thermally rearranged to the formal Diels‐Alder product 7.