A beta-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 alpha-hydroxy epoxides followed by an in situ equilibration via retro aldol reactions. Various attempts of a conversion to the title hydrocarbon failed. (c) 2008 Elsevier Ltd. All rights reserved.