Determination of the Relative Configuration of Terminal and Spiroepoxides by Computational Methods. Advantages of the Inclusion of Unscaled Data

• DOI: 10.1021/acs.joc.6b02129
• Publication Date: 2016-11-04T22:29:41Z
• Authors: María M. Zanardi; Alejandra G. Suárez; Ariel M. Sarotti
• Keywords: Constructive; Scope (computer science); Chemical shift; Basis (linear algebra)

The assignment of the relative configuration spiroepoxides or related quaternary carbon-containing oxiranes can be troublesome and difficult to achieve. use GIAO NMR shift calculations provide helpful assistance in challenging cases structural elucidation. In this regard, DP4 probability is one most popular methods employed when only set experimental data available, though modest results were obtained dealing with spiroepoxides. Recently, we introduced an improved (DP4+) that includes both scaled unscaled computed at higher levels theory. Here, report a comprehensive study explore scope limitations DP4+ methodology stereoassignment terminal bearing wide variety molecular complexity conformational freedom. excellent correct classification achieved interpreted on basis constructive compensation errors upon using proton carbon data. advantages solving two case studies could not unequivocally assigned by NOE experiments are also provided.