Strong Axial Preference of 2-S Substituents in 3,4-Dihydro-2 H -1-Benzopyrans |
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| Authors: | Kaija Sipilä Jarno Kansikas |
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| Institution: | 1. Laboratory of Organic Chemistry, Department of Chemistry , University of Helsinki , University of Helsinki, PO Box 55, FIN-00014 , Finland;2. Laboratory of Inorganic Chemistry, Department of Chemistry , University of Helsinki , PO Box 55, FIN-00014 University of Helsinki, Finland |
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| Abstract: | The synthesis and crystal structure of a O,S,S-acetal derivative (1 R *,2 R *,2' S *)-1-(3,4-dihydro-2 H -1-benzopyran-2-ylthio)-2-phenyl-1-phenylthiopropan-2-ol 4 are reported. The 2-S-sidechain orientation in solution determined by OCHS signals in 1 H NMR spectra is mainly axial in all the 3,4-dihydro-2 H -1-benzopyran derivatives. Compound 4 crystallizes in the triclinic space group P 1 with an axial 2-S-sidechain and an intramolecular hydrogen bond between the OH and the ether oxygen with the O;;;O distance of 2.799(3) Å. |
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| Keywords: | Conformation Crystal Structure 2-S-3 4-dihydro-2 H -1-benzopyran Synthesis O S S-acetal |
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