A study of non-bonded interactions of nitro and nitronate substituents in inositols

Abstract
In the family of mutually interconvertible δ-O-methyl-deoxynitroinositols having the myo-5 (1), neo-2 (2), allo-5 (3), epi-1 (4), epi-6 (5), and cis(6)configurations the relative thermodynamic stabilities of the individual members and of the three corresponding sodium nitronates 1′, 3′, and 5′ were assessed by determining equilibria of epimerization at pH 8.2 and pH > 12. The orders of stability are [Formula: see text] and 1′ > 3′ > 5′. The equilibrium data, together with those previously obtained for the stereoisomeric series comprising the corresponding scyllo (7), myo-1 (8), epi-3 (9), and muco-3 (10) epimers and their nitronates 7′, 8′, and 9′, were compared with theoretical values that were obtained from calculated conformational energies. The non-bonded interactions of the nitro and the nitronate group were evaluated and variable energy parameters were devised on the basis of differing gauche arrangements.