1. Conformation of Sterically Hindered 4-Methyl-2-oxo-2-trityl-1,3,2-dioxaphosphorinane in the Solid State and the Solution.
- Author
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Kruszynski, R., Czubacka, E., Trzesowska-Kruszynska, A., Bartczak, T. J., Bruzik, K. S., Knopik, P., Kudzin, Z., Stec, W. J., and Wolf, W. M.
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CHEMICAL reactions , *CHLORIDES , *NUCLEAR isomers , *ENANTIOSELECTIVE catalysis , *NUCLEAR magnetic resonance spectroscopy , *X-ray crystallography - Abstract
The cis- and trans-2-methyl-2-oxo-2-trityl-1,3,2-dioxaphosphorinanes were obtained in the Arbuzov reaction of 2-methoxy-4-methyl-1,3,2-dioxaphosphorinane with trityl chloride. The NMR spectra (H, C and P) in solution indicated that trans isomer exists in the form of two noncongruent molecules and it adopts two different conformations: a halfchair and a sofa, while the cis isomer exists as the mixed half/chair-sofa conformer. The compounds crystallise as a pure chiral forms and as a racemates. The solid state structural studies show that NMR data are consistent with the single crystal X-ray analysis, but the conformation existing in the crystal structure is more complex than it can be supposed on sole NMR determination. Crystal data: cis-isomer chiral form: space group P3, a = 8.782, b = 8.782, c = 21.680, α = 90.00, β = 90.00, γ = 120.00, V = 1448.0; cis-isomer racemate: space group Pca2, a = 16.773, b = 8.491, c = 27.006, α = 90.00, β = 90.00, γ = 90.00, V = 3846.2; trans-isomer racemate: space group Cc, a = 16.133, b = 8.388, c = 16.158, α = 90.00, β = 117.20, γ = 90.00, V = 1944.8; trans-isomer chiral form: space group P 1, a = 8.397, b = 9.003, c = 14.944, α = 80.76, β = 74.38, γ = 63.31, V = 971.1). Graphical Abstract: The cis- and trans-2-methyl-2-oxo-2-trityl-1,3,2-dioxaphosphorinanes were obtained in the Arbuzov reaction of 2-methoxy-4-methyl-1,3,2-dioxaphosphorinane with trityl chloride. The obtained compounds were characterized by X-ray crystallography and NMR spectroscopy in solid state and solution.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
- Published
- 2011
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