>> I have updated my Analysis and run Problem Resonances on the project (no any
>> spectra). Indeed, LeuCda* (or Cdb*) is no longer linked to both Hda* and
>> Hdb*, but it is linked to Cg only. Thus, Hd and Cd of Leu do not get linked
>> at all and the same goes for Val Cg and Hg.
>
>This is as it should be! These are ambiguous prochirals, and so the links
>cannot be made between them unless there is experimental evidence, i.e. to
>tie one shift to another.
>
>Considering Leu; CDa and CDb both point to CD1 and CD2, likewise HDa* and
>HDb* to both HD1* and HD2* (i.e. stereospecifically ambiguous). If it is
>not known if CDa resonance is really CD1 or CD2 then you cannot tie it to
>a particular H resonance, that is until you see the interaction between
>two resonances in the form of a peak with the right dims. Until an
>unambiguous bound relationship can be established between prochiral H & C
>resonances the a/b labels are independent (and default to up/down field).
>
Yes, this is correct when you are doing assignment within Analysis. But in
my case I have imported the assignment and I know that protons at, say,
1.1ppm are attached to the carbon at, say, 22.2ppm. However, I do not know
it is delta1 or delta2 group of Leu and I arbitrary assigned these
resonances to delta1 group of Leu. Thus I expect to see in the Quality
Report table that these two resonances are bound. It is not about
stereospecific assignment, it is about belonging the two resonances to one
methyl group.
Cheers,
Vitaliy
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