Automated structure elucidation of two unexpected products in a reaction of an α,β‐unsaturated pyruvate

Abstract

The reaction between an alpha,beta-unsaturated pyruvate and ethyl diazoacetate (EDA) yielded two unexpected products. The structures of these products were determined by automated elucidation of the chemical structures using spectroscopic inputs of a series of 1D and 2D NMR data using the computer program ACD/Structure Elucidator, StrucEluc. The formation of these products is rationalised. Their structures were also confirmed by x-ray crystallography.

Are Deterministic Expert Systems for Computer-Assisted Structure Elucidation Obsolete?

“…This does not indicate that additional data may not be necessary in certain situations, for example, when a large molecule has a structure with a deficit of hydrogen atoms and a significant number of heteroatoms. Deterministic systems can successfully solve such tasks as evidenced by Table and the materials presented in our previous publications. − ,− …”

“…Expert systems allowing computer-assisted structure elucidation based on spectral data, including multidimensional NMR data, have proven valuable in the elucidation of complex organic molecules. Articles published in recent years have reported on systems capable of elucidating the chemical structures of even complex natural products. − Some studies ,− report the application of expert systems to the elucidation of novel structures of natural compounds. Until recently, most publications presented examples that showed the capabilities of the expert systems in terms of solving tasks that would commonly be dealt with by qualified spectroscopists.…”

“…Articles published in recent years have reported on systems capable of elucidating the chemical structures of even complex natural products. [1][2][3][4][5][6][7][8][9] Some studies 7,[10][11][12][13][14][15][16][17][18][19][20][21] report the application of expert systems to the elucidation of novel structures of natural compounds. Until recently, most publications presented examples that showed the capabilities of the expert systems in terms of solving tasks that would commonly be dealt with by qualified spectroscopists.…”

Structural revisions of natural products by Computer-Assisted Structure Elucidation (CASE) systems

“…The effectiveness of such an approach has previously been proven on a series of difficult problems. [7][8][9] If the researcher wants to include a set of specific User Fragments in the structure elucidation then the program can assign the experimental chemical shifts to carbon atoms within the fragments and include these fragments directly into the MCD.…”

“…Examples of the application of ESs for such purposes have been published elsewhere (see, for instance, refs. [1][2][3][4][5][6][7][8][9]. Reviews of the state of the science in regards to CASE developments were produced by Jaspars 10 (1999) and Steinbeck 11 (2004).…”