The total syntheses of three enantiomerically pure non-proteinogenic amino acids, l-norvaline, γ-oxonorvaline, and syn-γ-hydroxynorvaline, are reported. The chromatography-free route pivoted on the construction of highly enantiomerically enriched substituted α-amino-γ-oxopentanoic acid, from which all three members were accessed divergently via chemoselective and stereoselective reductions. The rapid synthesis of this key α-amino-γ-oxopentanoic acid was achieved by a highly diastereoselective crystallisation-driven three-component Mannich reaction from the readily available building blocks acetone, glyoxylic acid monohydrate, and (S)-(4-methoxyphenyl)ethylamine. The enantiomeric purity of all target molecules was confirmed by HPLC analysis, either of the amino acids or their derivatives.

Protodenitration, a direct reduction of nitroalkanes to corresponding alkanes, already spans two centuries and is enabled by various reagents. This mini-review provides a historical development of the fundamental transformation and highlights the governing position of the Ono-Tanner reaction employing tributyltin hydride. Due to the unchallenged dominance of the toxic tributyltin hydride and environmentally unpopular solvents sharply contrasting with modern ecological trends, the current situation was dubbed "the last fortress of tin's tyranny."[a

Berkeleylactone A is a potent 16-membered macrolactone antibiotic, recently isolated from a coculture of Berkeley Pit Lake fungi. Although its antimicrobial activity has already been investigated, little is known about...

The Front Cover visually represents our review “The Last Fortress of Tin′s Tyranny – Protodenitration of Nitroalkanes“. ”Once upon a time, in a small corner of a faraway land full of nitroalkanes, a small town called “Protodenitrations” started coming to life. Unfortunately, a sneaky tin, hungry for power, soon took the opportunity and overtook the small, still fragile community, establishing himself as the king. The kingdom ruled by Tin The Tyrant has expanded since then, spreading its roots all over the continent. Despite a few attempts to dethrone the Tyrant, he remains undefeated. However, rumors are starting to spread that an army of reagents is beginning to gather. Could the end of the last fortress of the tyranny of tin be in sight?“ This review provides the historical development and highlights the governing position of the Ono–Tanner reaction employing tributyltin hydride. Due to the unchallenged dominance of the toxic tributyltin hydride, the current situation was dubbed “the last fortress of tin′s tyranny.” The authors would like to thank Katarína R. Detková for the graphic project and creation. More information can be found in the Review by P. Jakubec et al.