- Stereoselective synthesis of alicyclic ketones: A hydrogen borrowing approach
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A highly diastereoselective annulation strategy for the synthesis of alicyclic ketones from diols and pentamethylacetophenone is described. This process is mediated by a commercially available iridium(III) catalyst, and provides efficient access to a wide range of cyclopentane and cyclohexane products with high levels of stereoselectivity. The origins of diastereoselectivity in the annulation reaction have been explored by a series of control experiments, which provides an explanation for how each stereocentre around the newly forged ring is controlled.
- Armstrong, Roly J.,Akhtar, Wasim M.,Frost, James R.,Christensen, Kirsten E.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
(2019/11/13)
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- Stereoselective Synthesis of Cyclohexanes via an Iridium Catalyzed (5 + 1) Annulation Strategy
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An iridium catalyzed method for the synthesis of functionalized cyclohexanes from methyl ketones and 1,5-diols is described. This process operates by two sequential hydrogen borrowing reactions, providing direct access to multisubstituted cyclic products with high levels of stereocontrol. This methodology represents a novel (5 + 1) strategy for the stereoselective construction of the cyclohexane core.
- Akhtar, Wasim M.,Armstrong, Roly J.,Frost, James R.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
p. 11916 - 11920
(2018/09/27)
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- Synthesis and conformation studies of a dodecaazanonacyclotetratetracontane
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Compound 3 was prepared by self-assembly of 1,3,5-pentanetriamine and aqueous formaldehyde in quantitative yield (Figure 1). This molecule can exist in four well-defined diamond-lattice conformations of symmetries D(2d), S4, C(2v) and D(2d). Low-temperature 13C NMR spectroscopy indicates the existence of three main conformers; their relative populations depend on the solvent used. An extra set of low- intensity lines is also observed. A conformation interconversion scheme is proposed; it involves two additional less populated quasi-diamond-lattice intermediates derived from a helix compressed along its axis. One of these is trapped as a 1:2 clathrate with 1,4-dioxane; its crystal structure is reported.
- Suissa, M. Rachel,Romming, Christian,Dale, Johannes
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p. 3055 - 3065
(2007/10/03)
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- FURTHER EXTENSIONS OF THE KINETIC ENOLATE METHOD FOR TERPENOID SYNTHESES
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New stereorandom syntheses of juvabione and dehydrojuvabione using kinetic enolates as synthons are described.
- Ferrino, S. A.,Maldonado, L. A.
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p. 925 - 932
(2007/10/02)
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- Synthetic Studies in Carbocyclic Systems : Part I - A new Synthesis of Nopinone
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Base-induced intramolecular nucleophilic displacement of the tosyloxy group of 4-isopropyl-7-tosyloxycyclohexanone affords nopinone , identical with an authentic specimen.
- Murthi, G. S. S.,Mazumder, Alok
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p. 339 - 340
(2007/10/02)
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