Eberhard Wenschuh

The conformational behaviour of some p-tolylsulphlnamides

Abstract Eight sulphinamides of the type p -CH 3 C 6 H 4 -S(O)-NHR, where R represents an aliphatic group, were investigated by means of IR spectroscopy. The doubling of the SO stretching frequency of the free molecules is discussed in terms of conformational isomerism, originated by the rotation around the S-aryl axis. The two conformers participate differently in the H bond, NH-OS. The doublets of the NH bands in the spectra of the free molecules occur because of the existence of two conformations and are due to the rotation about the SN axis. The H bonds influence the conformational behaviour of the molecules. The H bond enthalpies are estimated by calorimetric measurements to lie between about 6 and 20 kJ for the complete association of one mol monomer. The NMR spectra show that the NH proton is part of the spin-spin coupling system.

BEITRÄGE ZUM REAKTIVEN VERHALTEN VON SULFINSÄUREDERIVATEN VIII1: ZUR SYNTHESE VON SULFINYLAZIRIDIDEN

Abstract Darstellung und spektroskopische Charakterisierung (1H-NMR-, IR-, Ramanspektren) von Sulfinylazirididen werden beschrieben. Reaktionen mit H-aziden nukleophilen Partnern fuhren vorwiegend zu polymeren Produkten und nur in wenigen Fallen zu β-funktionellen N-Ethylsulfinamiden. Preparation and spectroscopic properties (1H-NMR-, IR-, Raman spectra) of sulfinyl-aziridides are described. Reactions with H acidic nucleophiles lead mainly to polymeric products and only in some cases to the analogous β-functionally N-ethylsulfinamides.

A NEW SYNTHETIC ROUTE TO SULFINIC ACID ESTERS

Abstract Dialkylsulfoxylates undergo reactions with alkylhalides and other alkylating agents to give sulfinic acid esters, which were characterized by IR-, 1H-NMR- and mass-spectra.

ENANTIOSELECTIVE EFFECTS IN ASSOCIATION II

Abstract The title compound (I) has been synthesized for the first time. Their spectra of the pure enantiomer and the racemic mixture (both dissolved in CCl4 to an association allowing concentration) are different from each other in characteristic features. The differences vary on changing the temperature and/or concentration and are discussed in terms of thermodynamic properties of the H bond, linking the molecules by NH[sbnd]OS-bridges. In particular, the free NH bands of the pure enantiomer are about 10% less intensive than those of the racemic mixture under the same conditions, the case of high, association-free dilution excluded. Rather dramatic findings can be reported describing the association between the pure (R)-butan-2-ol and I. Only by change of the configuration of one of the partners differences of about one order of magnitude in the equilibrium constants are obtained.