(1S,2R,2′S)- and (1S,2S,2′S)-1-phenyl-2-phenylthio-2-(tetrahydropyran-2′-ylthio)ethanol diastereoisomers at 193 K

Abstract

In the synthesis of 1-phenyl-2-phenylthio-2-(tetrahydropyran-2-ylthio)ethanol, C(19)H(22)O(2)S(2), four diastereoisomers are formed. Two non-centrosymmetric enantiomeric forms which crystallize in space groups P2(1)2(1)2(1) and Pna2(1) are presented. The former has an intramolecular hydrogen bond between the hydroxyl group and the O atom of the tetrahydropyran ring. In the latter isomer, the hydroxyl group forms an intermolecular hydrogen bond to the O atom of the tetrahydropyranyl group of a neighbouring molecule, joining the molecules into chains in the c-axis direction; the O.O distances are 2.962 (4) and 2.764 (3) A, respectively. The tetrahydropyran rings are in chair conformations in both isomers and the S side chain has an equatorial orientation in the former, but an axial orientation in the latter molecule.

Teaching modulated structures - a project-based approach

“…References We have studied the syntheses and structures of novel O,S,S-acetal compounds where the O atom belongs to the tetrahydropyran (THP) ring with the Ssidechain at 2-position and the other S atom of the dithioacetal moiety is substituted by an aryl group. [1][2][3][4][5][6] Alkylations of these lithiated O,S,S-acetals showed remarkable diastereoselectivity, which was rationalized by the locked conformation of the five-membered ring caused by lithium-to-oxygen coordination. [5] 2-(Phenanthren-9-ylthiomethylthio)tetrahydropyran (1) is the only crystalline starting material for the lithiations obtained so far.…”

“…At low temperatures, Pr moments does not order for PrMn2-xFexGe2 with x = 0.8 and 1.0 and PrMn1.2Co0.8Ge2. These results are compared with NdMn2-xFexGe2 [3] and LaMn2-xFexSi2 [4] in respect to the effect of Fe and Co substitution on the interplane magnetic couplings. The F-AF transition at a critical Mn-Mn interatomic distance dMn-Mn within the (001) Mn layers (intralayer) is larger than the value (2.865 Å) for pure Mn compounds (e.g.…”

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