Synthesis, conformation and dynamics of 4,4,5,5,6,6,7,7,8,8-decamethyl-1-oxa-spiro[2.5]octane and 1,2,3,3,4,4,5,5,6,6-decamethyl-cyclohexene

The fragmentation of a suitable methylated 1-oxa-spiro[2.5]octane yields permethyl-cyclohexene. The activation parameters for the chair to chair interconversion of the 1-oxa-spiro[2.5]octane and the half-chair to half-chair interconversion of permethyl-cyclohexene were determined via bandshape analyses of exchange-broadened 1H and 13C NMR spectra, respectively.