Sulfur-carbon-phosphorus anomeric interactions. 4. Conformational analysis of 2-(diphenylphosphinoyl)-1, 3-dithiane

E Juaristi, L Valle, BA Valenzuela…

Index: Juaristi,E.; Valle,L.; Valenzuela,B.A. Journal of the American Chemical Society, 1986 , vol. 108, p. 2000

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Citation Number: 48

Abstract

Abstract: Proton NMR spectroscopy and X-ray crystallographic studies demonstrate the predominance of the axial conformer of 2-(diphenylphosphinoyl)-l, 3-dithiane (1). Chemical equilibration of anancomeric models (2~ i 3) allows quantitative determination of the conformational free energy in 1, 1.0 kcal/mol, which corresponds to an anomeric effect of 3.74 kcal/mol, the largest yet measured. Comparison of the structural data for 1-ax and 2 ( ...