The first syntheses of two quinoline alkaloids found in the medicinal herb Ruta chalepensis are reported via the conjugate addition of an o-iodoaniline to an acetylenic sulfone, followed by Pd-catalyzed carbonylation, intramolecular acylation of the corresponding sulfone-stabilized carbanion, and reductive desulfonylation.

The preparation of alkynes from carbonyl compounds via a one-carbon homologation has become a very useful pathway for the synthesis of acetylenic compounds, both internal and terminal. This tutorial review provides an overview of the different methods available for this transformation, including their scope and limitations, recent developments and applications in total syntheses.

Photochemically, covalent cycloaddition products of flavoquinone and acetylenic enzyme inhibitors have been prepared and elucidated, which appear analogous to flavoprotein-inhibitor complexes (monoamine and lactate oxidase). The additions occur with inhibitors of general type H C = C — C H < at the C (4a )=N(5 ) azomethine grouping of oxidized flavin. The spectral properties of adducts and thei...

Synthetic access to regiodifferentiated meta-amino phenols is described. The strategy relies upon distinct deprotonation conditions to afford regioisomeric thermodynamic and kinetic dienes that undergo a tandem Diels-Alder and retro-Diels-Alder sequence with assorted acetylenic dienophiles to afford a range of aromatic products.

Two new acetylenic fatty acids (1, 2), a new triglyceride (3), along with eleven known compounds including 3-oxo-11alpha,12alpha-epoxyurs-13beta,28-olide (4) previously reported as a synthetic compound, have been isolated from the leaves of Hymenodictyon excelsum. The structural identification was established from spectroscopic data.

Glycolide and lactide function as the commonly used diester monomers for preparation of high-molecular weight, degradation-prone (co-)polyesters. Both glycolide lactide-based polymers are widely in medicine, pharmaceuticals, food industry, additive technologies. This review on diesters, spanning research from 1833-1854 to present, encompassing their structural peculiarities, physico-chemical pr...

Cycloaddition of 3,4-dibromofuran with azo diesters proceeds by a Diels–Alder reaction followed by a novel rearrangement to give 3,5dibromotetrahydropyridazin-4-ones. Variable-temperature NMR spectroscopy shows four separate conformations at low temperature attributed to restricted rotation about the carbamate functions. The ethyl compound decomposes upon storage with loss of the carbamate grou...