Norpinyl‐Norbornyl‐Umlagerungen: Mesomeriestabilisierte Bicyclo[3.1.1]hept‐2‐ylkationen

Abstract

Norpinyl-Norbornyl Rearrangements:Resonance-Stabilized Ricyclo~3.l.l]hept-2-yl Cations 2-Phenylbicyclo[3.1 .l]hept-2-yl cations (Sc), generated by solvolysis of the 4-nitrobenzoate 8, undergo norpinyl-norbornyl rearrangement to a minor extent ( < 6 % in water, < I % in methanol). The acid-catalyzed alkoxy exchange of 2,2-dimethoxybicyclo[3.1 .l]heptane (13) proceeds without skeletal rearrangement. The solvolysis of bicyclo(3.1 .l]hept-3-en-2-yl-4-nitrobenzoate (19) is complicated by 0-acyl cleavage but the hydrolysis of the allylic bromide 21 and the nitrous acid deamination of the corresponding amine give bicyclo[3.1 .l]hept-3-en-2-01 (18) exclusively.

Degenerate thermal isomerizations of bicyclo[3.1.1]hept‐2‐ene: strategy and analysis

“…The degenerate thermal isomerization demonstrated the [1,3] sigmatropic carbon shifts vividly, but a full account of the thermal chemistry of 1 was not developed further. Several more effective syntheses of bicyclo[3.1.1]hept‐2‐ene have been contributed . Only three citations of the Dietrich and Musso degenerate thermal isomerization accomplished in 1974 have been provided in 2008 and 2009 by SciFinder .…”