Electronegative functional groups

The liquid enthalpy of formation difference between 1-hexyl and 1-heptyl hydroperoxides is almost twice that of a normal enthalpy of formation methylene increment of about 25 kJmol . But which of these two, if either, is correct For hydrocarbon snb-stituents bonded to electronegative functional groups, the secondary isomers are more stable than the n-isomer. Accordingly, either the 1- or 4-heptyl hydroperoxide, or both, have an inaccurate enthalpy of formation because the primary isomer is reported to have the more negative enthalpy of formation. All of the enthalpies of formation for the Cg and C7 hydroperoxides cited in Reference 2 come from a single source. There is a reported value for the gas phase enthalpy of formation of fert-butyl hydroperoxide that is 11 kJ mol less negative than the value in Reference 2. 

Electron-deficient olefins, asymmetric epoxidation, 386-91 Electron diffraction dialkyl peroxides, 713 ozonides, 721, 723 1,2,4-trioxolanes, 740 see also Gas electron diffraction Electron-donating substituents ene reactions, 841 sulfonyl peroxides, 1005-7 Electronegative functional groups,... 

Carboxylic acid derivatives (or acyl derivatives), RC—G, have the OH replaced by another electronegative functional group, G. such that it can be hydrolyzed back to the acid ... 

The reduction of carbon-carbon double bonds requires the presence of electronegative functional groups capable of forming a complex with Cr. Again, the problem of the compatibility of other functional groups with Cr must be condsidered. The essentially total lack of stereospecificity in the reduction of such substituted alkenes also severely limits the synthetic applicability of this reduction reaction. 

We know from C-NMR spectroscopy that subshtution with an electronegative functional group causes a diminishing downheld chemical shift for the carbon atoms along the alkyl chain (see Fig. 2.6). This pattern is interrupted for the y-carbon, which experiences a typical upheld shift instead. If we apply this knowledge to our alkyl phosphanes, we will expect that there should be an upheld shift due to y-subshtution for PPr"3 and PBu"3, but not for PBu 3 as the latter has tcrt-butyl substituents for which the phosphoms atom is 6 and not y. 

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