Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The formation and trapping of bicyclo[3.1.0]hex-(1,5)-ene and bicyclo[4.1.0]hept-(1,6)-ene from the corresponding vicinal dibromides is described. ... All new compounds had analyses, nmr and mass spectra which were consistent with the assigned structures.