190005-08-4Relevant academic research and scientific papers
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
, p. 5368 - 5371 (2017)
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.
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.
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.
