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.
A general synthetic route of dihydroagarofuran sesquiterpenoid from α- (-)-santonin
Tu, Yong Qiang,Sun, Liang Dong
, p. 7935 - 7938 (1998)
A general and efficient approach for synthesis of dihydroagarofuran sesquiterpenoid, the core structure of the polyol esters extensively present in the Celastraceae plants, has been developed by a series of transformations, which mainly include three creative and synthetically valuable conversions: the strategic double-bond shifting of 3, the versatile rearrangement of epoxide 5 generating two key functions, the C5-OH and 7,11- Double-bond, and the stereoselective cyclization/reduction of 8 constructing the tetrahydrofuran ring of 11. Thus the sesquiterpenoid 3α,6α, 12- trihydroxy-dihydoagarofuran 1 was synthesized.
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.
A formal synthesis of l-α-santonin from chiral α,β-epoxyeudesmanolide via enzyme-catalyzed hydrolysis
Shimizu,Akita,Oishi,Inayama
, p. 1160 - 1162 (1994)
(4S,5R)-Epoxy-(3S)-hydroxy-(10S)-7α,11βH-eudesman-6α,12-olide 4 and (4R,5S)-epoxy-(3S)-hydroxy-(10R)-7β,11αH-eudesman-6β,12-olide 5 were obtained from (±)-3 using yeast and (3S)-acetoxy-(4S,5R)-epoxy-(10S)- 7α,11βH-eudesman-6α,12-olide 8 was produced from (±)-8 using lipase, respectively. New total synthesis of l-α-santonin (9), and its Δ(4(14))- isomers (10 and 11) were accomplished by a short step synthesis using the optically active key intermediate (10S)-8 (prepared by asymmetric hydrolysis of (±)-8).
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.
Biotransformation of 6α-santonin and 1,2-dihydro-α-santonin by Acremonium chrysogenum PTCC 5271 and Rhizomucor pusillus PTCC 5134
Gandomkar, Somayyeh,Habibi, Zohreh
, p. 59 - 63 (2015/01/08)
Biotransformation of 6α-santonin (1) and 1,2-dihyro-α-santonin (2) by two fungal strains Acremoniumchrysogenum (Cephalosporium chrysogenum) and Rhizomucor pusillus has been investigated for the firsttime. After 8 days of incubation of 1 by A. chrysogenum, four known metabolites including 1,2-dihydro-α-santonin (2) (30%), 8α-hydroxyl-α-santonin (3) (22%), 15-hydroxy-α-santonin (4) (15%) and 4,5-dihydro-α-santonin (5) (10%) were obtained. Incubation of 1 by R. pusillus afforded two metabolites 2 (45%) and 3(20%). Biotransformation of 1,2-dihyro-α-santonin by A. chrysogenum produced tetrahydro-α-santonin(6) with 52% yield and tetrahydroartemisin (7) with 33% yield. By R. pusillus, the yields of 6 and 7 were32% and 21%, respectively. The structures of the products were identified on the basis of spectroscopic data.
A facile double-bond functionization of a eudesmane sesquiterpene lactone to form endocyclic α,β-unsaturated lactone
Sun, Liangdong,Tu, Yongqiang
, p. 723 - 725 (2007/10/03)
A one-step procedure for introducing double bond at C7-C11 position of eudesmane sesquiterpene compounds is reported, which is important in the synthesis of a number of natural bioactive sesquiterpenes possessing an α,β-unsaturated lactone moiety.
POTENTIAL ALLELOPATHIC ACTIVITY OF SEVERAL SESQUITERPENE LACTONE MODELS
Macias, Francisco A.,Galindo, Juan Carlos G.,Massanet, Guillermo M.
, p. 1969 - 1978 (2007/10/02)
A collection of 12 natural and synthetic sesquiterpene lactones with eudesmanolide, melampolide, cis,cis-germacranolide, and guaianolide skeletons have been prepared and tested as allelochemicals.The effect of a series of aqueous solutions at 10-4-10-9 M of this collection is evaluated.The specific structural requirements related to their activity is discussed.The natural sesquiterpene lactones soulangianolide A, melampomagnolide A and B, zaluzanin C and isozaluzanin C have been synthesized from costunolide, parthenolide and dehydrocostuslactone using SeO2 and tert-butylhydroperoxide.The structures of the synthetic compounds were established by NMR spectroscopy. Key Word Index - Sesquiterpene lactones; melampolides; cis,cis-germacranolides; guaianolides; eudesmanolides; allelopathy; Lactuca sativa.
