Michel Gacek

N-quaternary compounds—XXVIII : Circular dichroism of α-trimethylammonium acids

Abstract The dichroic absorption of α-trimethylammonium carboxylic acids has been compared with that of α-amino acids. The quaternary acids were synthesized by methylation of amino acids or by the Menschutkin reaction between bromo acids and trimethylamine. The stereochemical course in the Menschutkin reaction is discussed. Rate of racemisation in alkaline solution of the synthesized quaternary acids has been determined.

N-quaternary compounds—IXL : Circular dichroism of α-trimethylammonio aldehydes

Abstract (S)-α-Trimethylammonio aldehydes have been synthesised over several steps from corresponding amino acids. The dichroic carbonyl absorption can be rationalised in terms of the Octant Rule with the assumption of a preferred conformation. The chiroptical properties of intermediate α-phthalimido aldehydes have also been investigated.

Metahalones, a new class of metaphase inhibitors.

We have now extended our work on this class of substances and have attempted to establish the structure-activity relationship. The results suggest that the metaphase-inhibitory activity is associated with the 2-0~0 group and the 5-halogen, and that certain substituents in other positions are permissable for the retainment of activity. We should like to suggest the name Metahalones for this class of inhibitors. Meta from metaphase, ha2 from halogen and one because the activity is associated with the one-form of the 2-hydroxy group; O-substituted derivatives as shown below are inactive whereas N-substituted derivates are active.

N-quaternary compounds—XLIII synthesis and circular dichroism of α-amino and α-N,N,N-trimethylammonio acid amides

Abstract CD spectra of α-trimethylammonio acid amides contain 2 or 3 absorption bands in the 200–260 nm region. CD spectra of α-amino acid amides also contain multiple bands in this region. The possible origin of the CD bands is discussed.

N-quaternary compounds—XLIV: Synthesis and circular dichroism of α-N,N-dimethylamino and α-N,N,N-trimethylammonio ketones

Abstract CD spectra of acyclic α-N,N-dimethylamino ketones exhibit two absorption bands of opposite sign at ca . 240 and 305–315 nm. Both bands are ascribed to the same conformers. On protonation only one CD band is seen. The single CD band of α-N,N,N-trimethylammonio ketones has the same sign and almost the same wavelength maximum as the protonated amino ketones.