Interactions intramoléculaires—XIX: Constantes de couplage vicinales, équilibres conformationnels et interactions gauches (séries cyclohexanique et cyclohexénique)

NMR parameters are determined and identified for the four stereoisomers of 3,4-dimethyl methoxycarbonylcyclohexane (d₃-2,2,3,4,5,5), the two stereoisomers of 2-methyl methoxycarbonylcyclohexane (d₅-2,3,4,5,5) and 3-methyl 4-X cyclohexene (d₃-3,6,6) (X = COOCH₃, CH₂OH, CH₂Cl). For the axial COOCH₃ substituted cyclohexane, the vicinal coupling constants are in agreement with the ring deformation. Different conformational equilibria are estimated and discussed, especially in relation to the inequality of gauche interactions between two cis vicinal substituents.