We report counter‐intuitive axial preferences in non‐stereochemically biased, selectively fluorinated methoxycyclohexanes. These pseudo‐anomeric effects are apparent when electronegative CF2 groups are placed at the C‐2, C‐4 and C‐6 positions of the cyclohexane ring to render the C‐3/5 axial hydrogen atoms electropositive. The electrostatic interaction between these axial hydrogen atoms and the ‐OMe oxygen is stabilising. The effect is explored using high‐level ab initio and DFT calculations in the framework of NBO, QTAIM and NCI analysis across a range of derivatives, and experimentally (19F{1H}‐NMR at −80 °C) for some illustrative examples. The effect is significant in energy terms for a weak interaction, and illustrates a new stereoelectronic aspect attributed to selective fluorine substitution in organic chemistry.

Crystals of ~-chloro-~-valerolactam are monoclinic with space group P2~/e and Z= 4. The lattice constants at room temperature are a=11.73, b=6-20, c=9.51 A., ,8=112-0 °. The structure was solved from a minimum function M4 which was directly computed and contoured at the machine output. Both b-and c-axis data were refined separately with a least-squares program and the results are compared. The molecule has a half-chair conformation with the chlorine atom in equatorial position. The peptide linkage NH-CO has the cis configuration. Unusual bond lengths are not observed.

A laboratory activity is described for senior high school or first year undergraduate level students that illustrates key concepts linked to extractive metallurgy. This experiment demonstrates preferential binding of a methoxyphenolic oxime ligand to Cu 2+ in the presence of other transition metal ions in aqueous solution. The students are tasked to investigate the importance of the spatial relationship between the oxime and phenol group of two potential ligands by performing a series of short and simple tests. The objective is achieved by identifying which methoxyphenolic oxime ligand selectively and rapidly forms an isolable precipitate with Cu 2+ ions. Only one of the potential ligands exhibits a clear preference for binding to Cu 2+ , and this can easily be identified visually (and confirmed by UV−visible spectroscopy if desired). The experiment has successfully been employed as part of an extracurricular laboratory course involving groups of 25−30 high school students.