2205-32-5Relevant academic research and scientific papers
Chemoenzymatic approaches to the synthesis of the (1S,2R)-isomer of benzyl 2-hydroxycyclohexanecarboxylate
Tsunekawa, Ryuji,Hanaya, Kengo,Higashibayashi, Shuhei,Shoji, Mitsuru,Sugai, Takeshi
, p. 84 - 89 (2017/12/06)
We examined ten strains of cultured whole-cell yeasts for the asymmetric reduction of commercially available ethyl 2-oxocyclohexanecarboxylate, and found that the (1S,2S)-stereoisomer of ethyl 2-hydroxycyclohexanecarboxylate was the major stereoisomer produced by Williopsis californica JCM 3600. The ethyl group of the ester was then substituted with a benzyl group with low volatility and increased hydrophobicity to facilitate the isolation of the expected product. Incubation with W. californica furnished benzyl (1S,2S)-2-hydroxycyclohexanecarboxylate (>99.9% ee) in 51.0% yield together with its (1R,2S)-isomer (>99.9% ee) in 35.4% yield. Upon treatment of the same substrate bearing the benzyl ester with a screening kit of purified overexpressed carbonyl reductases (Daicel Chiralscreen OH), two enzymes (E031, E078) furnished the (1R,2S)-isomer as the major product. With another enzyme (E007), the (1S,2R)-isomer was obtained, but its ee was very low (25.6%). The highly enantiomerically enriched (1S,2S)-isomer obtained by W. californica was transformed to the (1S,2R)-isomer (>99.9% ee), whose availability until now has been low, in 43.3% yield over two steps involving tosylation and subsequent inversive attack with tetrabutylammonium nitrite.
INHIBITORS OF INFLUENZA VIRUSES REPLICATION
-
Page/Page column 96, (2012/06/30)
Methods of inhibiting the replication of influenza viruses in a biological sample or patient, of reducing the amount of influenza viruses in a biological sample or patient, and of treating influenza in a patient, comprises administering to said biological sample or patient an effective amount of a compound represented by Structural Formula (I): or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula (I) are as described herein. A compound is represented by Structural Formula (I) or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula (I) are as described herein. A pharmaceutical composition comprises an effective amount of such a compound or pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, adjuvant or vehicle.
INHIBITORS OF INFLUENZA VIRUSES REPLICATION
-
Page/Page column 127-128, (2012/06/30)
Methods of inhibiting the replication of influenza viruses in a biological sample or patient, of reducing the amount of influenza viruses in a biological sample or patient, and of treating influenza in a patient, comprises administering to said biological sample or patient an effective amount of a compound represented by Structural Formula (I): or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula (I) are as described herein. A compound is represented by Structural Formula (I) or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula (I) are as described herein. A pharmaceutical composition comprises an effective amount of such a compound or pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, adjuvant or vehicle.
Delineating origins of stereocontrol in asymmetric Pd-catalyzed α-hydroxylation of 1,3-ketoesters
Smith, Alexander M. R.,Rzepa, Henry S.,White, Andrew J. P.,Billen, Denis,Hii, King Kuok
supporting information; experimental part, p. 3085 - 3096 (2010/07/17)
Systematic studies of reaction conditions and subsequent optimization led to the identification of important parameters for stereoselectivity in the asymmetric α-hydroxylation reaction of 1,3-ketoesters. Enantioselectivities of up to 98% can be achieved for cyclic substrates and 88% for acyclic ketoesters. Subsequently, the combination of cyclic/acyclic ketoester, catalyst, and oxidant was found to have a profound effect on reaction rates and turnover-limiting steps. The stereochemistry of the reaction contradicts that observed for other similar electrophilic substitution reactions. This was rationalized by transition-state modeling, which revealed a number of cooperative weak interactions between oxidant, ligand, and counterion, together with C-H/π interactions that cumulatively account for the unusual stereoselectivity.
A practical synthesis of enantiopure N-carbobenzyloxy-N′-phthaloyl-cis-1,2-cyclohexanediamine by asymmetric reductive amination and the Curtius rearrangement
Matsuo, Jun-ichi,Okano, Masahiko,Takeuchi, Kosuke,Tanaka, Hiroyuki,Ishibashi, Hiroyuki
, p. 1906 - 1910 (2008/02/13)
Enantiomerically pure N-carbobenzyloxy-N′-phthaloyl-cis-1,2-cyclohexanediamine was synthesized by the asymmetric reduction of a β-enamino ester formed from benzyl 2-oxocyclohexanecarboxylate and (R)-phenylethylamine, followed by hydrogenolysis, phthaloyla
Palladium-catalyzed cyclization of alkenyl β-keto esters in the presence of chlorotrimethylsilane
Pei, Tao,Widenhoefer, Ross A.
, p. 650 - 651 (2007/10/03)
PdCl2(CH3CN)2 catalyzed the cyclization of alkenyl β-keto esters in the presence of a stoichiometric amount of SiMe3Cl to form 2-carboalkoxycyclohexanones in good yield with excellent regioselectivity.
