- STEREOSELECTIVE SYNTHESIS OF 3,4-DISUBSTITUTED CYCLOPENTANONES AND RELATED COMPOUNDS
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Methods and materials for preparing optically active 3,4-disubstituted cyclopentanones are disclosed. The method includes hydrolyzing one or more compounds represented by Formula (13), or removing an ester moiety from a compound represented by Formula (18).
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Page/Page column 43
(2010/11/25)
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- Double Asymmetric Hydrogenation of Conjugated Dienes Catalysed by Ruthenium-binap Complexes
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Buta-1,3-diene-2,3-dicarboxylic acid is smoothly hydrogenated in the presence of ruthenium-(R)-binap complexes as a catalyst via two consecutive 1,2-hydrogen additions, giving rise to (S,S)-2,3-dimethylsuccinic acid with 98percent diastereoisomeric excess and 96percent enantiomeric excess.
- Muramatsu, Hitoshi,Kawano, Hiroyuki,Ishii, Youichi,Saburi, Masahiko,Uchida, Yasuzo
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p. 769 - 770
(2007/10/02)
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- Stereoselective homogeneous hydrogenation. The basis of preferential anti-isomer formation in acyclic systems
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Directed homogeneous hydrogenation of olefins derived from methyl acrylate proceeds with high selectivity.The reactant must possess a polar substituent at a chiral centre situated in the α'-position; this may be -OH, CO2R or NHCOR.The catalyst should be a cationic chelating rhodium biphosphine complex.In all cases high anti-stereoselectivity is observed in the reduced product, and this can be rationalised by a simple and general model.With an optically active catalyst, efficient kinetic resolution occurs, providing a means of access to optically active acrylates.Experimental details of typical hydrogenation reactions are provided.
- Brown, John M.,Cutting, Ian,James, Alun P.
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p. 211 - 217
(2007/10/02)
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- HIGHLY DIASTEREOSELECTIVE TANDEM ALKYLATION OF ACYCLIC α,β-UNSATURATED ESTERS BASED ON THE NOVEL USE OF DITHIOACETAL UNIT
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Highly diastereoselective tandem alkylation process of acyclic α,β-unsaturated esters was developed based on the novel use of dithioacetal as a stereocontrolling unit.
- Kawasaki, Hisashi,Tomioka, Kiyoshi,Koga, Kenji
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p. 3031 - 3034
(2007/10/02)
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- OXIDATIVE COUPLING REACTIONS UNDER PTC CONDITIONS
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Succinic acid derivatives have been prepared from cyanohalides under PTC conditions in good yields.
- Gogte, V.N.,Natu, A.A.,Pandit, V.S.
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p. 4131 - 4134
(2007/10/02)
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- DIMETALATED TERTIARY SUCCINAMIDES. ALKYLATION AND ANNELATION REACTIONS
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The reactions of dimetalated succinamides 1 with a variety of electrophiles give 2,3-disubstituted adducts (2) with high diasterioselectivity and annelated products (6-9).
- Mahalanabis, K.K.,Mumtaz, M.,Snieckus, V.
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p. 3971 - 3974
(2007/10/02)
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