alkene 8. An entry point to this sequence from carbocycle 12 became evident, allowing us to approach the problem from 9 by adapting our previously reported cycloisomerization method. In the forward sense, this molecular reorganization is initiated by a photochemical cycloaddition to generate cyclobutane 10. An unusually mild Cope rearrangement within 10 produces cyclooctadiene 11, a reactive species that readily isomerizes to enone 12 in the presence of a proton shuttle. We previously established that this reaction provides 12 (X = Y = H) as a single isomer; however, a strategy to control absolute stereochemistry remains elusive because the stereodetermining event occurs in the photochemical step. To overcome this limitation, we considered introducing the C3 tertiary alcohol of 1 into 9 (X = Me, Y = OH). We reasoned that this chiral center could guide the initial [2+2] photocycloaddition, thereby establishing a stereoselective entry point to the 5-8-5 polycycle (12).