“…Based on preceding photochemical transformations, we believed that the dihydrohomobarrelenones 4 would be eligible for photoisomerizations, forming complex polycyclic compounds . The formed norcarane derivates would include fully substituted chiral cyclopropanes, which are often considered challenging synthetic targets . To our delight, the photoisomerization proceeded smoothly when subjecting a mixture of cycloadduct 4 e / 4 e′ to light in CHCl 3 (3 x 3 W, 365 ± 5 nm), yielding the tetracyclic norcarane 8 in 47 % yield, >20:1 d.r., and maintaining the enantiomeric excess (Scheme a).…”