- Chemoenzymatic enantioselective synthesis of 2-substituted glycerol derivatives
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2-Substituted glycerol derivatives 4a-g were resolved by acylation with vinyl butyrate in the presence of lipases in organic media. The reverse reaction, the enzymatic hydrolysis of the corresponding butyrates 5a-g, was also highly stereoselective and pro
- Bolduc, Melanie,Bergeron, Jerome,Michaud, Annie,Pelchat, Nicholas,Morin, Pierre,Dasser, Mohammed,Chenevert, Robert
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experimental part
p. 428 - 433
(2012/07/28)
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- Synthesis of the C7-C23 fragment related to iriomoteolide-1a via B -alkyl suzuki-miyaura cross-coupling and indium-mediated aldehyde allylation
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Synthesis of the C7-C23 fragment and its 18R,19S-diastereomer of iriomoteolide-1a has been accomplished from the C7-C12 allyl bromide, the C13-C16 vinyl iodide, and the C17-C23 alkyl iodide fragments. These fragments were assembled first by the B-alkyl Suzuki-Miyaura cross-coupling to give the C13-C23 intermediate. The latter, after being transformed into the C13 aldehyde, was coupled to the C7-C12 allyl bromide in the presence of indium powder in THF-H2O (1:1) at 70deg;C to the fully functionalized C7-C23 fragment with orthogonal protecting groups at C19 (PMB ether), and C9, C14, and C22 (TBS, TES, and TBS ethers, respectively). Formation of the characteristic six-membered C9/C13-hemiacetal ring has been demonstrated after global desilylation using pyridine-buffered HF.
- Liu, Yuanxin,Wang, Jian,Li, Huoming,Wu, Jinlong,Feng, Gaofeng,Dai, Wei-Min
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scheme or table
p. 2184 - 2188
(2010/10/21)
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- Development of a multikilogram synthesis of a chiral epoxide precursor to a CCR1 antagonist. Use of in situ monitoring for informed optimisation via fragile intermediates
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The optimisation and scale up of a manufacturing route to a key intermediate, acetic acid 4-acetylamino-3-(2-methyl-oxiranyl- methoxy)phenyl ester (2), utilising a SNAr coupling, the hydro- genation of a nitro moiety and the conversion of a chi
- Ange, Debra,Booker, James E. M.,Pedge, Nicholas,Sinclair, Rhona,Sleigh, Chris,Stefinovic, Marijan,Vaz, Luis-Manuel,Way, Edward
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experimental part
p. 72 - 84
(2010/05/02)
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- USE OF INTERMEDIATES ((R ) -2,2, 4-TRIMETHYL-L, 3-DIOXOLANE-4-YL) METHANOL (A), 3-F LUORO-4-NITRO-PHENOL (B) AND 1- (4-CHLORO- BENZYL) -PIPERIDIN-4-YLAMINE (C)
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The present invention relates to novel processes for the preparation of intermediate compounds which can be used to prepare therapeutic agents. The present invention also relates to novel intermediate compounds which can be used to prepare therapeutic agents. More specifically, the invention relates to the use of intermediates ((R) -2,2,4-trimethyl-l, 3- dioxolane-4 -yl) methanol (A), 3-f luoro-4-nitro-phenol (B) and 1- (4-chloro-benZyl) -piperidin-4-ylamine (C).
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Page/Page column 5-6; 17
(2009/04/25)
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- An alternative approach to (S)- and (R)-2-methylglycidol O-benzyl ether derivatives
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This report describes the gram scale synthesis of (S)- and (R)-2,2,4-trimethyl-4-(hydroxymethyl)-1,3-dioxolanes using the Sharpless asymmetric dihydroxylation (AD) of the Weinreb amide of 2-methyl-2-propenoic acid. The 2-methylglycerol acetonides resultan
- Avenoza, Alberto,Cativiela, Carlos,Peregrina, Jesus M.,Sucunza, David,Zurbano, Maria M.
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p. 1383 - 1388
(2007/10/03)
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- Facile Chemoenzymatic Preparation of Enantiomerically Pure 2-Methylglycerol Derivatives as Versatile Trifunctional C4-Synthons
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Both enantiomers of a series of synthetically valuable 2-methylglycerol derivatives have been prepared with >99percent ee using a chemoenzymatic reaction sequence.The introduction of chirality was achieved by enantioselective esterification of 1,2-O-protected 2-methylglycerol 3 or enantioselective hydrolysis of its butyryl ester 4.The enzymatic reaction proceeded with unusually high selectivity and velocity for a primary alcohol (ester) substrate.
- Wirz, Beat,Barner, Richard,Huebscher, Joseph
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p. 3980 - 3984
(2007/10/02)
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- ENZYMATIC ENANTIOSELECTIVE HYDROLYSIS OF 2,2-DIMETHYL-1,3-DIOXOLANE-4-CARBOXYLIC ESTERS
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2,2-dimethyl-1,3-dioxolane-4-carboxylic acid derived chiral building blocks were prepared from substituted α,β-unsaturated acids with high enantiomeric purities by enzymatic hydrolysis of their n.butyl esters.
- Pottie, M.,Eycken, J. Van der,Vandewalle, M.,Dewanckele, J. M.,Roeper, H.
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p. 5319 - 5322
(2007/10/02)
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- SUBSTRATE SPECIFICITY AND ENANTIOSELECTIVITY OF PENICILLINACYLASE CATALYZED HYDROLYSIS OF PHENACETYL ESTERS OF SYNTHETICALLY USEFUL CARBINOLS
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Penicillinacylase from E. coli, immobilized on Eupergit C beads catalyzes the hydrolysis in water/CH3CN 10:1, at pH 7.5 and 23 deg C, of a set of O-phenylacetate esters of primary carbinols.The highest enantioselectivity is observed in the case of the 2,2-dimethyl-1,3-dioxolane-4-methanols structurally related to the penicillin (1) framework.Minor modifications of this basic structure are not altering the acceptability by the enzyme, but significantly decrease the enantioselectivity of the hydrolysis, as does the use of benzene as solvent and Sepharose-bound enzyme.
- Fuganti, Claudio,Grasselli, Piero,Servi, Stefano,Lazzarini, Ameriga,Casati, Paolo
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p. 2575 - 2582
(2007/10/02)
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- ASYMMETRIC SYNTHESIS OF (R)-(+)- AND (S)-(-)-2,2,4-TRIMETHYL-4-(HYDROXYMETHYL)-1,3-DIOXOLANE OF HIGH ENANTIOMERIC PURITY
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The title compounds, 1 and 1', are readily available in four steps from 2-benzyloxymethyl-2-propen-1-ol, the key step being Sharpless asymmetric epoxidation to give the chiral epoxides 5 or 5'.The total chemical yield of 1 or 1' is 50percent, the final pr
- Tanner, David,Somfai, Peter
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p. 5985 - 5990
(2007/10/02)
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