Nature Communications, Published online: 12 September 2026; doi:10.1038/s41467-026-77436-w Chiral polycyclic spirocycles are privileged molecular scaffolds for drug discovery and asymmetric synthesis, yet their efficient stereoselective construction remains challenging. Here, the authors report a Pd/Sadphos-catalyzed asymmetric dearomative cascade that delivers polycyclic spiro enones with three contiguous stereocenters and exceptional stereoselectivity.