70150-60-6Relevant academic research and scientific papers
POLYMYXIN ANALOGS USEFUL AS ANTIBIOTIC POTENTIATORS
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Paragraph 0261, (2017/12/09)
The disclosure provides compounds of the formula (I) or a tautomer thereof, or a pharmaceutically acceptable salt of either of the foregoing. The variables A, R1, and R2 are defined in the disclosure. The disclosure further includes pharmaceutical compositions comprising a compound of formula I together with at least one pharmaceutically acceptable carrier. The disclosure also includes a method of sensitizing bacteria to an antibacterial agent, comprising administering to a patient infected with the bacteria, simultaneously or sequentially, a therapeutically effective amount of the antibacterial agent and a compound of formula (I).
Origin of the E/Z Selectivity in the Synthesis of Tetrasubstituted Olefins by Wittig Reaction of α-Fluorophosphonium Ylides: An Explanation for the Low Stereoselectivity Observed in Reactions of α-Alkoxy Aldehydes
Depré, Dominique,Vermeulen, Wim A. A.,Lang, Yolande,Dubois, Jean,Vandevivere, Jan,Vandermeersch, Jeremy,Huang, Longchuan,Robiette, Rapha?l
supporting information, p. 1414 - 1417 (2017/03/23)
A series of tetrasubstituted fluoroalkenes were synthesized in good yield and high E/Z selectivity (up to 96/4) by Wittig reaction between α-heterosubstituted ketones and α-fluorophosphonium ylides. A detailed study of factors that control stereoselectivity in these reactions shows that stereoselectivity is the result of stabilizing CH···F and N···C=O interactions in the addition TS leading to the E isomer. This analysis provides a rationale for the observed decrease in selectivity for reactions of stabilized ylides with α-alkoxy aldehydes.
Total Synthesis of Ovafolinins A and B: Unique Polycyclic Benzoxepin Lignans through a Cascade Cyclization
Davidson, Samuel J.,Barker, David
supporting information, p. 9483 - 9486 (2017/08/01)
Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans that contain a unique bridged structure containing a penta- and tetracyclic benzoxepin and an aryl tetralin. We report the first total synthesis of these natural products in which an acyl-Claisen rearrangement was initially utilized to construct the lignan backbone with correct relative stereochemistry. Judicious use of a bulky protecting group placed reactive moieties in the correct orientation, thereby resulting in a cascade reaction to form the bridged benzoxepin/aryl tetralin from a linear precursor in a single step. Modification of this route allowed the enantioselective synthesis of (+)-ovafolinins A and B, which confirmed the absolute stereochemistry, and comparison of optical rotation suggests that these compounds are found as scalemic mixtures in nature.
Total synthesis of (-)-bicubebin A, B, (+)-bicubebin C and structural reassignment of (-)-cis-cubebin
Davidson, Samuel J.,Pearce, A. Norrie,Copp, Brent R.,Barker, David
supporting information, p. 5368 - 5371 (2017/11/06)
The first total synthesis of (-)-bicubebin A, and two previously unreported dilignans, (-)-bicubebin B and (+)-bicubebin C has been achieved through the dimerization of (-)-cubebin, confirming the structure and absolute stereochemistry of (-)-bicubebin A. Analysis of the data for (-)-bicubebin B showed it matched that of reported compound (-)-cis-cubebin. The NMR data of the subsequently synthesized proposed structure of cis-cubebin confirmed that its original proposed structure was incorrect.
Syn-effect' in the diastereoselective alkylation of 3-[(E)-α,β-unsaturated-γ-substituted]-N-acyloxazolidinones
Jiménez, Jacqueline,Ramírez, Juáncarlos,Huelgas, Gabriela,Meléndrez, Ruth,Cabrera-Vivas, Blanca M.,Sansinenea, Estibaliz,Ortiz, Aurelio
, p. 4590 - 4597 (2015/06/08)
Synthetic methods for the formation of alkenes usually produce the E-alkene because it is more stable. However, in isomerization reaction (double bond migration) that takes place in α, β-unsaturated carbonyl compounds, when these carbonyl compounds are exposed to strong bases, furnish Z-alkenes highly stereoselective depending on the γ-substituent in the α, β-unsaturated carbonyl. This stereoselectivity can be attributed to the known Syn-effect. The synthetic value of this methodology is the achievement of chiral alcohol bearing an electron rich Z-alkene, as well as substituted, which was accomplished via removal of the oxazolidinone moiety under treatment with NaBH4, THF-H2O.
Highly efficient preparation of selectively isotope cluster-labeled long chain fatty acids via two consecutive Csp3-Csp3 cross-coupling reactions
Lethu, Sebastien,Matsuoka, Shigeru,Murata, Michio
supporting information, p. 844 - 847 (2014/03/21)
An efficient synthesis involving two copper-catalyzed alkyl-alkyl coupling reactions has been designed to easily access doubly isotope-labeled fatty acids. Such NMR- and IR-active compounds were obtained in excellent overall yields and will be further used for determining the conformation of an alkyl chain of lipidic biomolecules upon interaction with proteins.
Formal synthesis of berkelic acid: A lesson in α-alkylation chemistry
McLeod, Michael C.,Wilson, Zoe E.,Brimble, Margaret A.
experimental part, p. 400 - 416 (2012/02/15)
The full details of our enantioselective formal synthesis of the biologically active natural product berkelic acid are described. The insertion of the C-18 methyl group proved challenging, with three different approaches investigated to install the correc
A concise diels-alder strategy for the asymmetric synthesis of (+)-albicanol, (+)-albicanyl acetate, (+)-dihydrodrimenin, and (-)-dihydroisodrimeninol
Henderson, Jeff R.,Parvez, Masood,Keay, Brian A.
supporting information; experimental part, p. 3178 - 3181 (2009/12/05)
A short, mild, highly diastereo-, regio-, and stereoselective Diels-Alder strategy has been developed for the asymmetric synthesis of (+)albicanol, (+)-albicanyl acetate, (+)-dihydrodrimenin, and (-)-dihydroisodrimeninol.
Diastereomerically and enantiomerically pure 2,3-disubstituted pyrrolidines from 2,3-aziridin-1-ols using a sulfoxonium ylide: A one-carbon homologative relay ring expansion
Schomaker, Jennifer M.,Bhattacharjee, Somnath,Yan, Jun,Borhan, Babak
, p. 1996 - 2003 (2007/10/03)
An ylide-based aza-Payne rearrangement of 2,3-aziridin-1-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring-closure yields the desired pyrrolidine, thus completing the relay of the three-membered to the five-membered nitrogen-containing ring system. This process takes place with complete transfer of stereochemical fidelity and can be applied to sterically hindered aziridinols.
Tetrasubstituted pyrrolidines via a tandem aza-Payne/hydroamination reaction
Schomaker, Jennifer M.,Geiser, Andrea R.,Huang, Rui,Borhan, Babak
, p. 3794 - 3795 (2008/02/01)
A facile tandem aza-Payne/hydroamination reaction of aziridinol is reported, which yields highly functionalized pyrrolidines. Addition of alkynyl Grignards to 2,3-aziridinals yields, in most cases, high syn to anti ratios of the aziridinol. Treatment of the syn-aziridinol with base leads initially to an aza-Payne rearrangement, which juxtaposes the amine and the alkyne in favorable orientation to complete the hydroamination. The anti-aziridinol undergoes the aza-Payne rearrangement, but cannot proceed further with the hydroamination. Copyright
