An example of asymmetric Steglich-type rearrangement of enol lactones is reported. This highly enantioselective acyl transfer reaction is catalyzed by chiral isothiourea at ambient temperature and provides a useful synthetic approach to access enantioenriched spirotricyclic β,β′-diketones from a broad range of indanone or tetralone-derived lactones. Preliminary mechanistic studies suggest the initial