18409-93-3Relevant articles and documents
Synthesis of elemane bis-lactones structurally related to vernolepin
Blay, Gonzalo,Cardona, Luz,Garcia, Begona,Lahoz, Luisa,Pedro, Jose R.
, p. 3079 - 3082 (1998)
The chemical transformation of santonin into an elemane bis-lactone structurally related to the antitumour compound vernolepin is reported. The transformation of ring A of santonin into a hemiacetal δ-lactone was achieved in eleven steps. The spectroscopic characteristics of the synthetic product obtained in this way revealed that the proposed structure for the natural product should be revised.
Synthesis and Comprehensive Structural and Chiroptical Characterization of Enones Derived from (-)-α-Santonin by Experiment and Theory
Masnyk, Marek,Butkiewicz, Aleksandra,Górecki, Marcin,Luboradzki, Roman,Bannwarth, Christoph,Grimme, Stefan,Frelek, Jadwiga
, p. 4588 - 4600 (2016)
The aim of the present work is to explain the causes of the observed deviations from sector and helicity rules to determine the absolute configuration of optically active α,β-unsaturated ketones by means of electronic circular dichroism (ECD). To this end, a series of model compounds with a common decahydronaphthalene skeleton representing both cisoid and transoid enones were synthesized. In the framework of this work, detailed dichroic studies supported by single crystal X-ray analysis were performed where possible. To assist the achievement of the desired objectives the conformational flexibility of the selected cis-enones through the dependence of solvent and temperature on the ECD spectra were examined. All experimental studies were supplemented by detailed DFT calculations. A notable result of the study is assessing the applicability of the enone sector and helicity rules in dichroic studies and potential restrictions. To this end, a number of factors that could determine the signs of the individual Cotton effects has been considered. Among these nonminimum structure effects, i.e., twisting of the enone chromophore and nonplanarity of the enone double bond can be mentioned.
Studies on the stereostructure of eudesmanolides from Umbelliferae: Synthesis of 11β-angeloyloxy-α-santonin
Macias,Macias, Francisco A.,Aguilar,Aguilar, Jose Maria,Molinillo,Molinillo, Jose Maria G.,Massanet,Massanet, Guillermo M.,Fronczek,Fronczek, Frank R.
, p. 5439 - 5450 (1994)
The first approach to the synthesis of decipienin A (1) having the stereostructure b (11β-angeloyloxy-α-santonin) have been performed following three different synthetic routes. The key step on the synthetic procedures is the stereoselective hydroxylation at C-11 position. An evaluation of the different used routes is discussed. Comparison of spectroscopic data of compound 1b and those from the natural decipienin A suggests that a stereostructure type a could be assigned to the natural product.
Monolithic Silica Support for Immobilized Catalysis in Continuous Flow
Russell, M. Grace,Veryser, Cedrick,Hunter, James F.,Beingessner, Rachel L.,Jamison, Timothy F.
, p. 314 - 319 (2020)
Monolithic and packed-bed reactors featuring immobilized catalysts are well-precedented in continuous flow synthesis but can suffer from adverse pressure drops during use due to their small pore sizes and/or structural changes. Herein, we overcome this challenge with the synthesis of a structurally robust silica-based monolith featuring pore sizes on the millimeter scale. The 3-dimensional solid support structure is constructed from a polystyrene foam-based template and features a functional group handle that can be modified to display a reactive catalyst. Here we functionalize the support with palladium(0) for hydrogenation reactions and a modified proline catalyst for the alpha functionalization of aldehydes. Both reactors showed good activity and excellent catalytic longevity when utilized under continuous flow conditions. (Figure presented.).
Iridium-catalyzed intermolecular amidation of sp3 C-H bonds: Late-stage functionalization of an unactivated methyl group
Kang, Taek,Kim, Youngchan,Lee, Donggun,Wang, Zhen,Chang, Sukbok
supporting information, p. 4141 - 4144 (2014/04/03)
Reported herein is the iridium-catalyzed direct amidation of unactivated sp3 C-H bonds. With sulfonyl and acyl azides as the amino source, the amidation occurs efficiently under mild conditions over a wide range of unactivated methyl groups with high functional group tolerance. This procedure can be successfully applied for the direct introduction of an amino group into complex compounds and thus can serve as a powerful synthetic tool for late-stage C-H functionalization.
