2D-NMR-guided constitutional analysis of organic compounds employing the computer program COCON

The computer program COCON is introduced as a tool for the comprehensive st ructure elucidation of unknown organic compounds. In particular, structural proposals made on the basis of the molecular formula and of 2D-NMR experim ents can be analyzed for existence of alternative constitutions being in ag reement with the same data set. The computational speed grounds on the eval uation of ambiguous long-range connectivity information during the process of structure generation. The data set experimentally obtained for the marin e natural product oroidin (1) was selected, because proton-poor compounds u sually cause uncertainties in NMR-based structure determinations. The calcu lation results encourage to move from the experience-based analysis of NMR chemical shifts or of MS fragmentations to the automated evaluation of rout inely available connectivity information.