Stéréochimie de β-diols et de leurs dérivés cycliques–VI. Calcul empirique des déplacements chimiques en série dioxannique. Détermination et discussion des incréments de calcul

In order to calculate empirically proton chemical shifts in methyl 1,3-dioxans, the basic values for each proton of 1,3-dioxan itself are estimated. Then, using methyl derivatives in the chair conformation, the Δδ primary effects of methyl groups in any position are given. Modifications take place in molecules with butane gauche interactions and these secondary effects are evaluated. Analogous Δδ in both the cyclohexane and dioxane series are related to similar cyclic geometry. The presence of oxygen atoms however, introduces important discrepancies.