Russian Journal of Organic Chemistry,
37, 243-245 (2001)

An incredible source for assignment errors is provided by enone-fragments. A rough estimation based on our experience from our work of extracting CNMR-data from the public domain chemical literature shows that about 5% of all enone-systems are misassigned.

Compound IX from the above mentioned literature citation is given with the following assignment for the double-bond system:


The display within CSEARCH immediately shows an assignment problem for both signals associated with the double bond. The investment of 5 MILLISECONDS of CPU-usage detects this error.

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Page written on:  March 8th, 2008
Page online since:  March 8th, 2008