If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.


Analytical Chemistry

Calculated NMR Approach Improves Isomer Identification

A probability measure works unusually well in matching calculated and experimental spectra

by Stuart A. Borman
September 6, 2010 | A version of this story appeared in Volume 88, Issue 36

Using calculated NMR spectra to identify organic stereoisomers has just become easier, thanks to an approach developed by Cambridge University’s Steven G. Smith and Jonathan M. Goodman (J. Am. Chem. Soc., DOI: 10.1021/ja105035r). NMR spectra can be calculated for all diastereoisomers of individual organic compounds, making it possible to identify specific isomers by matching their experimental NMR spectra to calculated ones. But establishing a best fit has been difficult because errors in calculated and experimental spectra make agreement imperfect, even for correct matches. Smith and Goodman have now devised a probability measure called DP4 that works unusually well. They demonstrated the power of the approach by using it to identify the natural product tricholomalide A from 64 possible diastereoisomers. Dennis P. Curran of the University of Pittsburgh comments that he thought “assigning structures by calculating and comparing spectra was for the distant future, but the Smith-Goodman work suggests the future is here. There is potential for broad impact in the synthesis and natural product communities. I could even imagine this becoming a routine tool” that complements other assignment techniques.


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.