Protonation studies on epimeric homoallylic adamantylideneadamantyl alcohols, 4-methyleneadamantylideneadamantane, adamantylideneadamantane (Ad
Ad) and sesquihomoadamantene, and reaction of Ad
Ad and sesquihomoadamantene with NO2+BF4− and PhI(OH)OTs: a stable-ion NMR and theoretical (GIAO-NMR) study†
Abstract
Under stable-ion conditions, the “pseudo-axial” homoallylic Ad double-bond and the resulting carbocation undergoes rapid
Ad 5 reacts with FSO3H–CH2Cl2 to give the previously observed 5H+ (as a rapidly equilibrating pair of carbocations), together with the oxonium ion 6H+. The outcome of the reaction of Ad
Ad with NO2BF4, NOBF4 and with PhI(OH)OTs is the same, in all cases producing the spirocyclic