5453-93-0Relevant academic research and scientific papers
METHODS AND COMPOSITIONS FOR TERPENOID SYNTHESIS
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Paragraph 00107; 00108, (2018/04/13)
In one aspect, the disclosure relates to methods for preparation of terpene and terpene-like molecules. In a further aspect, the disclosure relates to the products of the disclosed methods, i.e., terpene and terpene-like molecules prepared using the disclosed methods. Intermediates for the synthesis of a wide variety of terpenoids are γ-allyl Knoevenagel adducts or quasi γ-allyl Knoevenagel adducts are disclosed. In various aspects, methods of preparing terpenoids through these intermediates are disclosed. The methods can comprise α-alkylation of an allylic electrophile followed by ring-closure metathesis to a polycyclic terpenoid structure. In a further aspect, the disclosure pertains to terpenoid frameworks, and compounds prepared via disclosed oxidation and substitution reactions on the disclosed terpenoid frameworks. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.
Selective Synthesis of Cyclooctanoids by Radical Cyclization of Seven-Membered Lactones: Neutron Diffraction Study of the Stereoselective Deuteration of a Chiral Organosamarium Intermediate
Just-Baringo, Xavier,Clark, Jemma,Gutmann, Matthias J.,Procter, David J.
supporting information, p. 12499 - 12502 (2016/10/13)
Seven-membered lactones undergo selective SmI2–H2O-promoted radical cyclization to form substituted cyclooctanols. The products arise from an exo-mode of cyclization rather than the usual endo-attack employed in the few radical syntheses of cyclooctanes. The process is terminated by the quenching of a chiral benzylic samarium. A labeling experiment and neutron diffraction study have been used for the first time to probe the configuration and highly diastereoselective deuteration of a chiral organosamarium intermediate.
Assembly of Terpenoid Cores by a Simple, Tunable Strategy
Lahtigui, Ouidad,Emmetiere, Fabien,Zhang, Wei,Jirmo, Liban,Toledo-Roy, Samira,Hershberger, John C.,Macho, Jocelyn M.,Grenning, Alexander J.
supporting information, p. 15792 - 15796 (2016/12/16)
Oxygenated, polycyclic terpenoid natural products have important biological activities. Although total synthesis of such terpenes is widely studied, synthetic strategies that allow for controlled placement of oxygen atoms and other functionality remains a challenge. Herein, we present a simple, scalable, and tunable synthetic strategy to assemble terpenoid-like polycycloalkanes from cycloalkanones, malononitrile, and allylic electrophiles, abundantly available reagent classes.
Total Syntheses of (-)-Mersicarpine, (-)-Scholarisine G, (+)-Melodinine E, (-)-Leuconoxine, (-)-Leuconolam, (-)-Leuconodine A, (+)-Leuconodine F, and (-)-Leuconodine C: Self-Induced Diastereomeric Anisochronism (SIDA) Phenomenon for Scholarisine G and Leu
Xu, Zhengren,Wang, Qian,Zhu, Jieping
, p. 6712 - 6724 (2015/06/08)
(Chemical Equation Presented) Enantioselective total syntheses of title natural products from a common cyclohexenone derivative (S)-18 were reported. Ozonolysis of (S)-18 afforded a stable diketo ester (R)-17 that was subsequently converted to two skeleta
Rh2(II)-catalyzed ester migration to afford 3 H-indoles from trisubstituted styryl azides
Kong, Chen,Driver, Tom G.
supporting information, p. 802 - 805 (2015/04/27)
Rh2(II)-Complexes trigger the formation of 3H-indoles from ortho-alkenyl substituted aryl azides. This reaction occurs through a 4π-electron-5-atom electrocyclization of the rhodium N-aryl nitrene followed by a [1,2]-migration to afford only 3H-indoles. The selectivity of the migration is dependent on the identity of the β-styryl substituent.
Catalytic asymmetric synthesis of sterically hindered tertiary α-aryl ketones
Doran, Robert,Guiry, Patrick J.
, p. 9112 - 9124 (2014/12/11)
The catalytic asymmetric synthesis of a series of tertiary α-aryl cyclopentanones and cyclohexanones has been accomplished via a Pd-catalyzed decarboxylative protonation of the corresponding α-aryl-β-keto allyl esters. Enantioselectivities of up to 92% ee and 74% ee were achieved for cyclopentanone and cyclohexanone substrates, respectively. The route described gives access to these important structural motifs in moderate to high levels of enantioselectivity. In particular, this is only the second direct approach for the preparation of tertiary α-aryl cyclopentanones. The synthetic approach allows for simple modification of the aryl group. Significantly, substrates containing sterically hindered aryl groups gave the highest levels of enantioselectivity, and these aryl groups were readily installed by a Pb-mediated arylation of a β-keto allyl ester.
Enantioselective total syntheses of leuconolam-leuconoxine-mersicarpine group monoterpene indole alkaloids
Xu, Zhengren,Wang, Qian,Zhu, Jieping
, p. 19127 - 19130 (2014/01/17)
A unified strategy allowing enantioselective total syntheses of (-)-mersicarpine, (-)-scholarisine G, (+)-melodinine E, (-)-leuconoxine, and (-)-leuconolam from a common cyclohexenone derivative was reported. The Suzuki-Miyaura reaction was used to couple
Enantioselective decarboxylative alkylation reactions: Catalyst development, substrate scope, and mechanistic studies
Behenna, Douglas C.,Mohr, Justin T.,Sherden, Nathaniel H.,Marinescu, Smaranda C.,Harned, Andrew M.,Tani, Kousuke,Seto, Masaki,Ma, Sandy,Novak, Zoltan,Krout, Michael R.,McFadden, Ryan M.,Roizen, Jennifer L.,Enquist Jr., John A.,White, David E.,Levine, Samantha R.,Petrova, Krastina V.,Iwashita, Akihiko,Virgil, Scott C.,Stoltz, Brian M.
supporting information; experimental part, p. 14199 - 14223 (2012/02/01)
α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursor: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center. Sly as a PHOX: The development of an enantioselective decarboxylative palladium-catalyzed allylic alkylation reaction, utilizing phosphinooxazoline ligands, is described. The catalyst is applied to a range of allyl enol carbonate, silyl enol ether, and allyl β-ketoester substrates to provide alkylated ketone products in excellent yield and good ee (see scheme). The utility of these products is demonstrated by their use in several asymmetric syntheses. Mechanistic studies are reported suggesting an unusual inner-sphere mechanism. Copyright
Combination of rearrangement with metallic and organic catalyses - A step- and atom-economical approach to α-spiroactones and -lactams
Boddaert, Thomas,Coquerel, Yoann,Rodriguez, Jean
experimental part, p. 5061 - 5070 (2011/10/09)
A general synthetic route to α-spirolactones and -lactams from 2-diazo-1,3-dicarbonyl compounds, (homo)allylic alcohols or amines and acrylic derivatives, involving a single consecutive reaction consisting of a Wolff rearrangement/α-oxo ketene trapping/cr
Synthesis and olfactory properties of spirocyclic Georgywood analogues
Kraft, Philip,Frech, David,Mueller, Urs,Frater, Georg
, p. 2215 - 2223 (2008/02/02)
Spirocyclic analogues of Georgywood (3) and unlike-10-acetyl-9,10- dimethylbicyclo[6.4.0]dodec-1(8)-ene (4), in which the acetyl moiety and the methyl substituent of C-10 are part of a cyclopentyl or cyclohexyl ring, were synthesized from 8a-homomyrcene (
