Solutions of the anti-self-dualSU(2) Yang-Mills equations gained from the inverse scattering method

By applying the inverse scattering method in connection with a dressing procedure a huge class of solutions of the anti-self-dualSU(2) Yang-Mills equation is obtained. This class contains also the well-known't Hooft instantions.     

Permethylcyclohexane

Permethylcyclohexane 2 has been synthesized and investigated by dynamic NMR spectroscopy. An unexpectedly low barrier (ΔG3₃₃₃ = 70.0 kJ/mol) of its chair-to-chair interconversion was found.     

Regioisomerism in the synthesis of a chiral aminotetralin drug compound: unraveling mechanistic details and diastereomer-specific in-depth NMR investigations

During chemical process development of a novel 2-aminotetralin derivative intended for use as an antidepressant, scrutiny of the byproduct present in the drug molecule revealed a set of regioisomers. Detailed studies showed that this impurity issue originated from an early synthetic step in which a brominated tetralone motif was generated in a ring-closing protocol. It was found that this reaction was accompanied by a migration of the aromatic bromo substituent via different bromonium species along two discrete pathways. This example of the halogen dance reaction resulted in the formation of a series of tetralone impurities with a bromine distributed across all available aromatic positions of the tetralin nucleus. Subsequently, when subjected to reductive amination conditions, each of these tetralones gave rise to pairs of aminotetralins in a diastereomeric relationship. NMR investigations revealed that the alicyclic portion of the compounds thus formed displayed very complex signal patterns, which required further in-depth studies using a variety of sophisticated techniques. As a result, a deep insight into the structural features of the current 2-aminotetralin family was obtained, which is emphasized by the definition of a novel "0.2 ppm rule" allowing the absolute configuration at tetralin C-2 to be determined.     

On the fifth forces

We discuss the possibility of fifth forces in relativistic gravitation theories of fourth order. The fifth force may be an analog to the weak forces in the theories of electroweak interactions.