- Total synthesis of (+/-)-frondosin B and (+/-)-5-epi-liphagal by using a concise (4+3) cycloaddition approach
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A recently developed (4+3) cycloaddition between dienes and furfuryl alcohols, as precursors of oxyallyl-type cations, has been used as a key step in the racemic syntheses of two natural products: frondosin B and liphagal. This work demonstrates the synthetic potential of this cycloaddition reaction, and offers a short synthetic route to an interesting family of natural products. A full account of these synthetic studies is presented, further illustrating the mechanism, scope, and limitations of this straightforward synthetic method for seven-membered rings. Cycloheptanes: Furfuryl alcohols serve as effective three-carbon dienophiles for a wide range of dienes in stereoselective cycloaddition reactions. This efficient reaction has been used to prepare two cycloheptanoid natural products, offering a conceptually straightforward and short synthetic entry into a biologically interesting class of polycyclic meroterpenoids (see scheme; TFA = trifluoroacetic acid). Copyright
- Laplace, Duchan R.,Verbraeken, Bart,Van Hecke, Kristof,Winne, Johan M.
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p. 253 - 262
(2014/01/17)
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- OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Compounds and compositions are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related to the misfolding of mutant opsin proteins and/or the mis-localization of opsin proteins. Compositions of these compounds alone or in combination with other therapeutic agents are also described, along with therapeutic methods of using such compounds and/or compositions. Methods of synthesizing such agents are also disclosed.
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- 5-Demethylretinal and its 5-(2)H, 7-(2)H and 5,7-(2)H2 isotopomers. Synthesis, photochemistry and spectroscopy
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All-trans-5-demethylretinal and its 5-(2)H, 7-(2)H and 5,7-(2)H2 isotopomers have been synthesized by means of a new and simple scheme.Using photochemistry, the 9-, 11- and 13-cis, as well as the 9,13- and 11,13-di-cis-isomers, were obtained.The structure
- Spijker-Assink, M. B.,Winkel, C.,Baldwin, G. S.,Lugtenburg, J.
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p. 125 - 131
(2007/10/02)
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- β-hydroxy Esters: (E)- versus (Z)-Enolate Geometry in Dianionic Claisen Rearrangements
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Control elements operative in the β-hydroxy ester dianionic Claisen rearrangements are probed.Stereochemistry at Cβ dictates face selectivity at Cα and Cβ' in 1->2-5, but only to the extent that it controls ester enolate g
- Kurth, Mark J.,Beard, Richard L.
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p. 4085 - 4088
(2007/10/02)
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