87785-63-5Relevant articles and documents
Acid-catalyzed cleavage of 4-halonortricyclanes. Evidence that the 2-norbornyl cation is an unsymmetrical species
Werstiuk, Nick Henry,Dhanoa, Daljit,Timmins, George
, p. 2403 - 2414 (2007/10/02)
Nortricyclanes 4a, 4c, 4d, and 4e were prepared and ring opened in D2SO4/CD3COOD.We found that the ratios of endo/exo deuterium at C(6) were 1.09+/-0.02, 1.30+/-0.03, 1.40+/-0.04, and 1.45+/-0.05 for cleavage of 4a, 4c, 4d, and 4e, respectively.The amount of 6,2-hydride shift decreased from 14.3+/-1.0percent in the case of nortricyclane (4a) to 6.0+/-1.1percent, 6.4+/-0.5percent, and 8.1+/-0.7percent for 4c, 4d, and 4e, respectively.Although four distinct mechanisms involving either nonclassical or rapidly-equilibrating cations are possible, cleavage most probably occurs to generate 6,2-unsymmetrically-bridged norbornyl cations.