THE PREDOMINANCE OF AXIAL CONFORMERS FOR TRANS-4-SUBSTITUTED CYCLOHEXENE OXIDES

A H-1 NMR conformational study of cis- and trans-4-substituted cyclohe xene oxides revealed an increased predominance, as compared with the p arent 4-substituted cyclohexenes, of the equatorial conformer for cis- isomers and a preference of the axial conformer far trans-isomers. The se conformational shifts can be rationalized in terms of intramolecula r dipole-dipole and/or steric interactions, However, molecular mechani cs calculations failed to reproduce the relative stability of the axia l conformer in trans-4-substituted cyclohexene oxides.