Notiz zur Synthese des Nonactins

With (?)-nonactic acid and the 8-epitosylate of benzyl (+)-nonactate usingWalden inversion (?)-nonactyl-(+)-nonactic acid is constructed. The latter forms by way of its imidazolide or its α-mercaptopyridyl ester the macrotetrolide nonactine in poor yield.     

On the electron impact induced hydroxyl loss from o-nitrostyrene

Unimolecular hydroxyl (OD^˙) loss from regio- and stereo-specifically labelled o-nitrostyrenes 1a, 1c and 1d results in the formation of an ion which upon collisional activation gives identical mass spectra. Suggestions are made which aim at explaining: (i) the loss of stereochemical integrity of the diastereotopic methylene hydrogens in the course of hydroxyl elimination; and (ii) to account for the collision induced losses of CO and HNC from the [M—hydroxyl]⁺ ion.     

Eine einfache,Fourier-gestützte Methode zur Beseitigung von Untergrund in einzelnen Spektral-Peaks

Analytical and Bioanalytical Chemistry - Durch energiedispersive Röntgenanalyse entstehen Spektren mit hohem Untergrundanteil. Es wurden von einzelnen Peaks die Koeffizienten A und B der...     

The partition function of degenerate quadratic functional and Ray-Singer invariants

The partition function of degenerate quadratic functional is defined and studied. It is shown that analytic torsion and similar invariants can be interpreted as partition functions of quadratic functionals.