Hi Don,
The total number of carbon peaks and the chemical shifts of specific
quaternary carbons are important to many Organic Chemists. I have seen
students running c13 nmr just to get a quaternary carbon to prove the
structure he has in his mind during preliminary structural identification
of a product.
Sandip
At 01:20 PM 11/27/2001 -0800, you wrote:
>My continuing debate with organic chemists about 13C NMR
>
>I have a continuing discussion with synthetic organic post-docs
>and grad students regarding efficient use of instrument time.
>When I explain that it is just as valid to extract 13C chemical
>shifts from HMQC and HMBC experiments as it is from 1D 13C spectra
>they first look puzzled, then they agree with me, but ultimately
>they say that even though they agree with me, thesis committees
>and journal referees expect them to run the traditional 13C spectrum.
>Now I am the first to admit there are probably plenty of situations
>where the 1D 13C is useful and even necessary. But I also believe
>that in most cases, if the HMQC and HMBC have been run, and the
>molecular weight is known from mass spec, then a 1D 13C is simply a
>very expensive formality.
>
>So here is my question:
>
>"For a particular compound, if all of the 13C chemical shifts can be
>identified from a combination of HMQC (or HSQC) and HMBC, shouldn't
>the organic chemistry community accept that a 1D 13C spectrum is
>unnecessary?"
>
>With your permission I will redistribute some of the more interesting
>responses.
>
>Thanks in advance.
>
>Don
>
>***********************************
>Donald M. Leek
>Chemical Biology NMR Laboratory
>Steacie Institute for Molecular Sciences
>National Research Council Canada
>Ottawa, Canada K1A 0R6
>phone: (613) 993-6356
> fax: (613) 952-0068
> email: don.leek@nrc.ca
>***********************************
Dr. Sandip K. Sur
NMR Manager and NMR Application Scientist
Department of Chemistry
University of Rochester
Rochester, NY 14627
Tel: 716) 275-4705
Fax: (716) 473-6889
Email: sur@chem.rochester.edu
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