Franck’s methodology

Recently, Juaristi and Cuevas (55) presented an application of Franck s methodology based on temperature-independent enthalpy AH° values (see Section Il.F., Eqs. [17] and [18]) to estimate the enthalpic contribution to the C—S—C—P(0) anomeric effect as A// g= 14kJ/mol [llkJ/mol in terms (56), but see also Section V.A]. 

Several values of the magnitude of the anomeric effect, AG, based on Franck s methodology (Section II.C) and calculated by us (54, 78, 98, 173, 354) for 2-substituted 5,5-dimethyl-l, 3-diheteroanes are collected in Table 19 (penultimate column) together with the appropriate values obtained by Juaristi s group (last column). The differences between these two sets of values can easily be explained as due to different methods of estimation of Fq factors (see Section II.C), different compounds studied, and different conformational probes applied. Nevertheless, except for dioxane derivative 110 (X = Y = O) the trends are the same. 

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