156386-82-2Relevant academic research and scientific papers
A novel synthesis of functionalized tetrahydrofurans by an Oxa-Michael/Michael cyclization of γ-hydroxyenones
Greatrex, Ben W.,Kimber, Marc C.,Taylor, Dennis K.,Tiekink, Edward R. T.
, p. 4239 - 4246 (2003)
An approach to highly functionalized tetrahydrofuran derivatives based upon a novel Oxa-Michael/ Michael dimerization of cis-γ-hydroxyenones is presented. The reaction begins with either 1,2-dioxines or trans-γ-hydroxyenones and proceeds by addition of on
Organocatalytic Enantioselective Selenosulfonylation of a C-C Double Bond to Form Two Stereogenic Centers in an Aqueous Medium
Chen, Zhili,Hu, Fangli,Huang, Shengli,Zhao, Zhengxing,Mao, Hui,Qin, Wenling
, p. 8100 - 8111 (2019/06/17)
Organocatalytic selenosulfonylation of the C-C double bond of α,β-unsaturated ketones to construct two contiguous stereogenic centers in an aqueous medium was described. A series of α-selenyl and β-sulfonyl ketones with various functional groups were synthesized in good yields and enantioselectivities with saturated NaCl solution as the solvent. In addition, this protocol had been successfully scaled up to a decagram scale via a simple workup procedure.
Lewis Acid Catalyzed [3+3] Annulation of Donor–Acceptor Cyclopropanes with γ-Hydroxyenones: Access to Highly Functionalized Tetrahydropyrans
Mondal, Keshab,Pan, Subhas Chandra
, p. 534 - 537 (2017/02/05)
Donor–acceptor cyclopropanes were engaged in a [3+3]-annulation reaction with γ-hydroxyenones. Sc(OTf)3was found to be the best catalyst, and 2,4,4,5-tetrasubstituted tetrahydropyran products were obtained in good yields under mild reaction con
Organocatalytic Asymmetric Synthesis of Chiral Dioxazinanes and Dioxazepanes with in Situ Generated Nitrones via a Tandem Reaction Pathway Using a Cooperative Cation Binding Catalyst
Liu, Yidong,Ao, Jun,Paladhi, Sushovan,Song, Choong Eui,Yan, Hailong
, p. 16486 - 16492 (2016/12/27)
Heterocyclic skeletons play major roles in pharmaceuticals and biological processes. Cycloaddition reactions are most suitable synthetic tools to efficiently construct chemically diverse sets of heterocycles with great structural complexity owing to the s
Stereoselective preparation of 3-alkanoylprop-2-en-1-ol derivatives
Sada, Mutsumi,Ueno, Shizue,Asano, Keisuke,Nomura, Kenichi,Matsubara, Seijiro
, p. 724 - 726 (2009/07/25)
3-Alkanoylprop-2-en-1-ol derivatives were prepared stereoselectively by ring-opening reaction of β,γ-epoxyketone with amines. Georg Thieme Verlag Stuttgart.
A new route to diastereonumerically pure cyclopropanes utilizing stabilized phosphorus ylides and γ-hydroxy enones derived from 1,2-dioxines: Mechanistic investigations and scope of reaction
Avery, Thomas D.,Taylor, Dennis K.,Tiekink, Edward R.T.
, p. 5531 - 5546 (2007/10/03)
A new chemical transformation for the construction of diversely functionalized cyclopropanes utilizing 1,2-dioxines and stabilized phosphorus ylides as the key precursors is presented. Through a series of mechanistic studies we have elucidated a clear understanding of the hitherto unknown complex relationship between 1,2-dioxines 1a-e, and their isomeric cis/trans γ-hydroxy enones (23 and 21a-e), cis/trans hemiacetals 24a-e, and β-ketoepoxides (e.g., 26), and how these precursors can be utilized to construct diversely functionalized cyclopropanes. Furthermore, several new synthetically useful routes to these structural isomers are presented. Key features of the cyclopropanation include the ylide acting as a mild base inducing the ring opening of the 1,2-dioxines to their isomeric cis γ-hydroxy enones 23a-e, followed by Michael addition of the ylide to the cis γ-hydroxy enones 23a-e and attachment of the electrophilic phosphorus pole of the ylide to the hydroxyl moiety, affording the intermediate 1-2λ5-oxaphospholanes 4 and setting up the observed cis stereochemistry between H1 and H3. Cyclization of the resultant enolate (30a or 30b), expulsion of triphenylphosphine oxide, and proton transfer from the reaction manifold affords the observed cyclopropanes in excellent diastereomeric excess. The utilization of Co(SALEN)2 in a catalytic manner also allows for a dramatic acceleration of reaction rates when entering the reaction manifold from the 1,2-dioxines. While cyclopropanation is favored by the use of ester-stabilized ylides, the use of keto- or aldo-stabilized ylides results in a preference for 1,4-dicarbonyl formation through a competing Kornblum-De La Mare rearrangement of the intermediate hemiacetals. This finding can be attributed to subtle differences in ylide basicity/nucleophilicity. In addition, the use of doubly substituted ester ylides allows for the incorporation of another stereogenic center within the side chain. Finally, our studies have revealed that the isomeric trans γ-hydroxy enones and the β-keto epoxides are not involved in the cyclopropanation process; however, they do represent an alternative entry point into this reaction manifold.
The first practical approach to optically pure cyclopropanes derived from trans γ-hydroxy enones
Palmer, Francine N.,Taylor, Dennis K.
, p. 1323 - 1325 (2007/10/03)
The optically pure cyclopropanes derived from trans γ-hydroxy enones were discussed. The trans γ-hydroxy enones were found to be prepared from reaction of stabilized ketoylides on optically pure α hydroxy aldehydes. The analysis showed that the use of light and a triplet sensitizer lead to a dramatic increase in reaction rate and isolated yield.
