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ARS Home Midwest Area Peoria, Illinois National Center for Agricultural Utilization Research Plant Polymer Research Research Publications at this Location





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Title:   Author  item
                                            Appell, Michaelitem
                                            Willett, Juliousitem
                                            Momany, Frank
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 5/7/2004
                                    Publication  Date: 6/17/2004
                                    Citation: Appell, M.D., Willett, J.L., Momany, F.A. Density functional study of the chair forms of alpha- and beta-d-allopyranose at the b3lyp/6-311++g** level. Midwest Theoretical Chemistry Conference. 2004. {abstract} p. 16.Interpretive Summary:
                                Technical Abstract: Geometry optimizations were carried out on the 4C1 and 1C4 chair conformations of allopyranose at the B3LYP/6-311++G** level of theory.  These density functional calculations will be compared to those of glucopyranose as a means to identify the effects of epimerization at the C-3 position.  The alph- and Beta-anomers of the gg, gt, and tg rotamer conformations were investigated, as well as the clockwise and counterclockwise hydroxyl orientations.  The 4C1 chair conformations of allopyranose are between 0.4-2.8 kcal/mol higher in energy than the lowest energy glucopyranose structure identified (alpha-gt-4C1 chair).  The lowest energy allopyranose structure found is the Beta-gg-4C1 chair conformation with the hydroxyls in the counterclockwise orientation.  The 1C4 chair conformations of allopyranose are 2.4-6.8 kcal/mol higher in energy than the Beta-gg-4C1 form.  All of the 1C4 chair conformations of allopyranose in this investigation have been found to be lower in overall energy than their glucopyranose counterparts.


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