- (8RS,5SR,7SR)-7-Benzoyl-8-hydroxy-8-phenylspiro[4.5]decan-1-one
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In the title compound, C23H24O3, the five-membered ring adopts a half-chair conformation and the cyclohexane ring is in a chair conformation. The benzoyl group and the phenyl ring are equatorially attached. The hydroxyl gr
- Surya Prakash Rao,Jayalakshmi,Chinnakali, Kandasamy,Fun, Hoong-Kun
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- Optimized Scalable Synthesis of Chiral Iridium Pyridyl-Phosphinite (Pyridophos) Catalysts
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Iridium catalysts with chiral P,N ligands have greatly enhanced the scope of asymmetric olefin hydrogenation because they do not require a coordinating group near the C=C bond like Rh and Ru catalysts. Pyridophos ligands, possessing a conformationally restricted annulated pyridine framework linked to a phosphinite group, proved to be particularly effective, inducing high enantioselectivities in the hydrogenation of a remarkably broad range of substrates. Here we report the development of an efficient scalable synthesis for the two most versatile Ir-pyridophos catalysts, derived from 2-phenyl-8-hydroxy-5,6,7,8-tetrahydroquinoline or the analogue with a five-membered carbocyclic ring, respectively, by modification and optimization of the original synthetic route. The optimized route renders both catalysts readily accessible in multi-gram quantities in analytically pure form in overall yields of 26–37 %, starting from acetophenone and cyclopentanone or cyclohexanone, respectively. A major advantage of the new synthesis is the efficient and practical kinetic resolution of the late-stage pyridyl alcohol intermediates with commercial immobilized Candida antarctica lipase B, giving access to both enantiomers of these catalysts as essentially enantiopure compounds. The catalysts are obtained as crystalline solids, which are air-stable and can be stored for years at ?20 °C without notable decomposition.
- Müller, Marc-André,Gani?, Adnan,H?rmann, Esther,Kaiser, Stefan,Maywald, Matthias,Roseblade, Stephen J.,Schrems, Marcus G.,Schumacher, Andreas,Woodmansee, David,Pfaltz, Andreas
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- HETEROARYLDIHYDROPYRIMIDINE DERIVATIVES AND METHODS OF TREATING HEPATITIS B INFECTIONS
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Provided herein are compounds useful for the treatment of HBV infection in a subject in need thereof, pharmaceutical compositions thereof, and methods of inhibiting, suppressing, or preventing HBV infection in the subject.
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Page/Page column 45; 46
(2019/01/17)
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- Microwave-mediated facile synthesis of steroid-like 1,5-diketones from Mannich salts
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A facile synthesis of some diketones that fit into a steroid motif was achieved from Mannich salts and cyclic ketones under microwave irradiation. Copyright Taylor & Francis Group, LLC.
- Rao, H. Surya Prakash,Poonguzhali,Senthilkumar
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p. 937 - 942
(2008/09/17)
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- Iridium catalysts with bicyclic pyridine-phosphinite ligands: Asymmetric hydrogenation of olefins and furan derivatives
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(Chemical Equation Presented) Superior bicyclics: Iridium catalysts as 1 derived from pyridine-phosphinite ligands considerably extend the scope of asymmetric hydrogenation. In addition to various unfunctionalized and functionalized olefins, furans, and benzofurans, for which no catalysts were known before, are also hydrogenated with high enantioselectivity (see scheme).
- Kaiser, Stefan,Smidt, Sebastian P.,Pfaltz, Andreas
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p. 5194 - 5197
(2007/10/03)
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- Novel domino products from the reaction of phenyl vinyl ketone and its derivatives with cyclic ketones
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Reaction of phenyl vinyl ketone with cyclopentanone under thermal conditions resulted in novel domino products, 1,5,9-triketones along with the expected 1,5-diketones. The 1,5,9-triketones were formed via a Michael-Michael-rearrangement pathway. On the other hand, reaction under basic conditions furnished a spiro[4.5]decanone, formed by domino pathways involving Michael-Michael-aldol condensation reactions. Microwave mediated reductive amination-cyclization of the 1,5,9-triketone furnished the perhydrocyclopenta[ij]quinolizine derivative.
- Surya Prakash Rao,Jeyalakshmi,Senthilkumar
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p. 2189 - 2199
(2007/10/03)
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- Surface-mediated Solid Phase Reaction. Part 6. Mukaiyama-Michael Addition of Silyl Ethers to Alkyl Vinyl Ketones on the Surface of Alumina: a Simple and Convenient Method for the Synthesis of 1,5-Diketones
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Michael addition of silyl enol and dienol ethers to alkyl vinyl ketones occurs in high yields through a simple solvent-free reaction on the surface of anhydrous zinc chloride-impregnated alumina to give 1,5-diketones.
- Ranu, Brindaban C.,Saha, Manika,Bhar, Sanjay
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p. 2197 - 2200
(2007/10/02)
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- NOVEL RING EXPANSION OF CYCLOPENTANONES TO SEVEN MEMBERED RINGS
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By treatment with BF3/ethyleneglycol, cyclopentanones with the carbonyl function at the C3-position of α-side chain undergo the ring cleavage to build up the seven membered rings, and this novel ring expansion was applied to the synthesis of bulnesol.
- Tanaka, Masakazu,Suemune, Hiroshi,Sakai, Kiyoshi
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p. 1733 - 1736
(2007/10/02)
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