peri-Interaction, ortho-interaction, and barriers to internal rotation. A dynamic nuclear magnetic resonance and molecular mechanics investigation of 1,2-dineopentylbenzene and 1,8-dineopentylnaphthalene

Abstract

For 1,2-dineopentylbenzene and 1,8-dineopentylnaphthalene, barriers to interconversion of enantiomeric trans-conformations of 5.8 and 7.4 kcal mol^–1 respectively have been measured by the dynamic n.m.r. method. Molecular mechanics calculations of the two molecules are reported and the results are discussed in terms of the relative importance of peri- and ortho-interactions.