The conformational analysis of saturated heterocycles. Part 76. Ring and nitrogen inversion in cis- and trans-1, 4, 5, 8-tetramethyldecahydropyrazino[2,3-b]pyrazine
Abstract
Variable-temperature protonand pulsed proton noise-decoupled carbon-13 Fourier transform n.m.r. have been used to determine the inversion barriers and conformations of cis- and trans-1, 4, 5, 8-tetra methyl decahydropyrazino[2,3-b]pyrazine. The rate processes causing the spectral changes are discussed.