“…Chromatography of trans,trans-12 and cis,trans-16 cleanly gave irons-bromo epoxide 11 and cisbromo epoxide 15, respectively. 4.23 ("q") 5.55 (t, J = 5 Hz) OAc Br<^Aj»Br C6 3.90 (m) 5.33 (t, J = 10.5 Hz) C8 4.25 (m) 5.43 (t, J = 9.5 Hz) c12 4.26 ("q") The cyclooctane ring is known to adopt a number of low energy conformations13 in which C-l, C-2, C-3, C-7, and C-8 atoms take up positions resembling the chair conformation of a cyclohexane ring. Examination of Table I demonstrates a close parallel between the multiplicities and spin coupling constants of the HCBr and HCO protons in the related sixand eight-membered ring isomers, adding additional support for the geometric assignments made in the cyclooctane series.…”