Helical primary structures of 1,2-spiroannelated five-membered rings: attempted synthesis of (±)-tetraspiro[4.0.0.0.4.3.3.3]heneicosane

A β-hydroxy ketone with a helical carbon skeleton of five 1,2-spiroannelated cyclopentane rings is the main product of a Lewis acid catalyzed rearrangement of suitable sized α-hydroxy epoxides followed by an in situ equilibration via retro aldol reactions. Various attempts of a conversion to the title hydrocarbon failed.