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Diels‐Alder between nitroalkenes derived from a sugar scaffold and cyclopentadiene were examined. Depending on chemical structure of nitroalkene and polarity of solvent used, the reaction proceeded via the formation of a nitronate intermediate. Cyclic nitronates highly functionalized were obtained as chemically stable and stereochemically pure compounds. [3,3] sigmatropic shift of these ones afforded the Diels Alder cycloadducts in quantitative yield. Mechanistic aspects of reaction between nitroalkenes and cyclopentadiene has been studied using DFT computational methods. Nitronate derivatives are attractive intermediates and open the way for the construction of valuable compounds with potential applications. [ABSTRACT FROM AUTHOR]

An experimental and computational study (including DFT calculations and distortion/interaction analysis) was conducted to assess the effect of the nitrone structure in the outcome of dipolar 1,3‐cycloadditions with levoglucosenone, a biomass derived chiral enone. While B3LYP/6‐31G* (the most popular method for modeling these reactions according to our literature search) provides qualitatively good results, large outliers were found for some systems versus experimental data. An exhaustive exploration of other levels allowed us to determine the most appropriate ones to predict simultaneously reactivity and selectivity. The systematically predicted high exo selectivity by the majority of the levels led us to reconsider our initial assignment for the reaction with the nitrone derived from piperidine, which resulted in the discovery of an interesting case of conformational dynamics. [ABSTRACT FROM AUTHOR]

A series of levoglucosenone‐derived thiosemicarbazones have been designed and synthesized following a simple and straightforward procedure. The in vitro antimycobacterial activity of the full library were evaluated against M. tuberculosis H37Ra, with 4 compounds being active in the 1.9–10.7 μg/mL concentration range. To determine the influence of the thiosemicarbazone fragment, the synthetic precursors were analyzed, as well as 50 structurally diverse triazoles and isoxazoles derived from levoglucosenone. Comparing the observed activities with the levels of cell viability in L929 cells at the MIC, it can be concluded that the derivatives reported in this work represent interesting candidates for further development of promising antituberculosis agents. [ABSTRACT FROM AUTHOR]

This article, published in the European Journal of Organic Chemistry, discusses the synthesis of cyclic nitronates using nitroalkenes derived from carbohydrates and cyclopentadiene. The authors conducted an experimental study and used DFT calculations to support their findings. The resulting cyclic nitronates were enantiomerically pure and chemically stable. For more information, readers can refer to the research article by M.I. Mangione and co-workers. [Extracted from the article]

A straightforward synthesis of a highly substituted biomass‐derived chiral pyrrolidine conveniently functionalized to obtain macrocycles through intramolecular "click" reactions is reported. The experimental difficulties encountered during the macrocyclization stage led us to conduct an extensive DFT study to understand the origins of the findings. The results suggest that the improper conformational landscape of the reactant precludes the pre‐organization required to connect the reactive moieties. We propose that the cumulative Boltzmann amplitudes of reactive conformations (CBAR) prove to be a simple and useful parameter to predict the success or failure of related transformations. [ABSTRACT FROM AUTHOR]

The design and synthesis of X‐shaped molecules bases on a central pyrene is reported. A Sonogashira cross‐coupling reaction was applied to successfully bond the pyrene core through acetylene linkages to electroactive dendrons moieties such as triphenylamine or carbazole. Dendrons were functionalized with bulky alkyl groups to disrupt π‐π stacking interactions and consequently affording soluble dendrimers. These novel π‐conjugated turtle‐shape dendrimers are organic materials with great potential applications in optoelectronic devices. Two novel turtle‐shape dendrimers with pyrene core and triphenylamine or carbazole dendrons were efficiently synthetized by C−C Sonogashira coupling. These dendrimers presents fully π‐conjugated structure and easy solubility in common organic solvents thus become prospective useful materials for the development of organic optoelectronic devices. [ABSTRACT FROM AUTHOR]

A sterereospecific and efficient synthesis of thiosugars derived from levoglucosenone and methyl α‐d‐glucopyranoside was developed by a domino epoxide ring opening‐ xanthate migration to afford 1,3‐oxathiolane‐2‐thiones in high yields. The stereochemical outcome of the new C–S bond was defined by the configuration of the starting materials. The 1,3‐oxathiolane‐2‐thiones were subsequently submitted to a second tandem reaction affording the corresponding 2,3‐episulfide alcohols. The thiosugars obtained are useful building blocks for the synthesis of thiooligosaccharides with potential biological properties. A stereospecific and efficient synthesis of thiosugars derived from levoglucosenone and methyl α‐d‐glucopyranoside was developed by a domino epoxide ring opening‐ xanthate migration to afford 1,3‐oxathiolane‐2‐thiones in high yields. [ABSTRACT FROM AUTHOR]

The need to find sustainable alternatives to reduce the dependence on fossil sources has led to significant research efforts on the conversion of biomass into platform chemicals. Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. The selective pyrolytic conversion of cellulose or cellulose-containing materials produces levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis. [ABSTRACT FROM AUTHOR]

The end-group-differentiating ozonolysis concept is discussed, with an emphasis on norbornene systems. Different remote functional groups in endo positions in norbornene derivatives are able to direct the primary ozonide fragmentation. By analysis of the factors affecting the regioselectivity, a rule to predict the direction of the primary ozonide rupture is formulated. These reactions give access to highly substituted cyclopentane rings and provide opportunities for their subsequent regioselective manipulation. [ABSTRACT FROM AUTHOR]

The Cover Feature shows a stunning event that takes place every few years in Patagonia, Argentina: the breaking of the Perito Moreno glacier. Such impressive spectacle is triggered by the pressure developed by the glacier, pushing water through the glacier tunnels underneath, which eventually causes tunnel growing and finally a dramatic collapse as the barrier breaks. In the same way, an interesting domino process towards useful thiosugars is initiated by the strain release involved in epoxide opening. More information can be found in the Full Paper by R. A. Spanevello et al. [ABSTRACT FROM AUTHOR]