transformation reaction using dimethylsulfoxonium methylide, a novel reaction was identified by which 5,6,7,8-tetrahydrocoumarin with the electron-withdrawing group at C3 was led to the spirobicyclo[3.1.0]hexane-cyclohexane derivative. Moreover, by establishing the scope of this reaction, it was confirmed that it is possible to apply this reaction to not only ring-fused α-pyrone derivatives but also a
6,7,8-tetrahydronaphthyl analogues have been synthesized via vinylation of cyclic ketones, subsequent lactonisation and thermally induced, inverse electron demand hetero Diels-Alderreaction. The diversity of the obtained products derives from the multiplicity of cyclic ketones and from the variety of dienophiles of the Diels-Alderreaction.