116660-75-4Relevant articles and documents
Oxidation of butane-1,3-, butane-1,4-, 2-methyl pentane-2,4- and 3-methyl pentane-2,4-diols by cerium(IV) in aqueous acidic medium catalyzed by rhodium(III)
Tandon, Praveen K.,Khanam, Shaista Z.,Yadav, Suresh C.,Shukla, Ritesh C.
scheme or table, p. 739 - 746 (2012/07/01)
The oxidation kinetics of butane-1,3-diol, butane-1,4-diol, 2-methyl pentane-2,4-diol and 3-methyl pentane-2,4-diol with cerium(IV) catalyzed by rhodium(III) in aqueous sulfuric acid showed a peculiar nature with respect to the variation in oxidant concentration, such that the reaction follows first-order kinetics in [Ce(IV)] at low [Ce(IV)] and then reaches a maximum with increasing [Ce(IV)], beyond which further increase in the oxidant concentration retards the rate. The rate shows direct proportionality with respect to [diol] at low concentrations, becoming independent of [diol] at higher concentrations. The rate is first order in catalyst. Retarding effects are observed when [H +] and [Ce(III)] are increased, while [Cl-] and hence ionic strength have a positive effect on the rate. Spectroscopic studies confirmed that the primary hydroxyl groups in butane-1,3-diol and butane-1,4-diol resulted in the formation of 3-hydroxy butanal and 4-hydroxy butanal, respectively. In the case of oxidation of the secondary hydroxyl groups in 2-methyl pentane-2,4-diol and 3-methyl pentane-2,4-diol, the products of oxidation were 4-hydroxy-4-methyl pentan-2-one and 4-hydroxy-3-methyl pentan-2-one, respectively.
Synthesis of valuable chiral intermediates by isolated ketoreductases: Application in the synthesis of α-alkyl-β-hydroxy ketones and 1,3-diols
Kalaitzakis, Dimitris,Rozzell, J. David,Smonou, Ioulia,Kambourakis, Spiros
, p. 1958 - 1969 (2007/10/03)
Regio- and stereoselective reductions of α-substituted 1,3-diketones to the corresponding β-keto alcohols or 1,3-diols by using commercially available ketoreductases (KREDs) are described. A number of α-monoalkyl- or dialkyl-substituted symmetrical as well as non-symmetrical diketones were reduced in high optical purities and chemical yields, in one or two enzymatic reduction steps. In most cases, two or even three out of the four possible diastereomers of α-alkyl-β-keto alcohols were synthesized by using different enzymes, and in two examples both ketones were reduced to the 1,3-diol. By replacing the α-alkyl substituent with the OAc group, 1-keto-2,3-diols, as well as 1,2,3-triols were synthesized in high optical purities. These enzymatic reactions provide a simple, highly stereoselective and quantitative method for the synthesis of different diastereomers of valuable chiral synthons from non-chiral, easily accessible 1,3-diketones.
Highly stereoselective reductions of α-alkyl-1,3-diketones and α-alkyl-β-keto esters catalyzed by isolated NADPH-dependent ketoreductases
Kalaitzakis, Dimitris,David Rozzell,Kambourakis, Spiros,Smonou, Ioulia
, p. 4799 - 4801 (2007/10/03)
(Chemical Equation Presented) The biocatalytic reduction of α-alkyl-1,3-diketones and α-alkyl-β-keto esters employing 1 of 20 different isolated NADPH-dependent ketoreductases proved to be a highly efficient method for the preparation of optically pure keto alcohols or hydroxy esters.
Zinc-promoted reactions. Part 5. The behaviour of alkyl substituted 1,3-diketones
Floris, Barbara,Luchetti, Luciana,Rosnati, Vittorio
, p. 4409 - 4418 (2007/10/02)
The zinc-promoted reaction of 2,4-pentanedione and related β-dicarbonyl substrates have been investigated under a variety of conditions. The results were explained according to a general mechanism, involving ionic and nonionic pathways.
Meerwein-Ponndorf-Verley-Type Reduction of Dicarbonyl Compounds to Hydroxy Carbonyl Compounds and α,β-Unsaturated Carbonyl Compounds to Allylic Alcohols Catalyzed by Zirconocene and Hafnocene Complexes
Nakano, Tatsuya,Umano, Shigetoshi,Kino, Yoshio,Ishii, Yasutaka,Ogawa, Masaya
, p. 3752 - 3757 (2007/10/02)
Group IVA metallocene complexes such as bis(η5-cyclopentadienyl)zirconium dihydrides, Cp2ZrH2 (1), and hafnium dihydrides, Cp2HfH2 (8), catalyze the chemoselective reduction of polycarbonyl compounds to hydroxy carbonyl compounds.For instance, the reduction of keto aldehydes 3-ketobutanal (2g) and 2-phenyl-2-ketoethanal (2h) proceeded selectively at aldehyde group to provide the corresponding hydroxy ketones 3g and 3h in 91percent and 93percent yields, respectively.Under similar conditions, however, cyclohexanediones were easily aromatized to benzenediols.On the other hand, 1 and 8 also catalyze the selective 1,2-reduction of various types of α,β-unsaturated carbonyl compounds, giving the corresponding allylic alcohols in good to excellent yields.Thus, steroidal dicarbonyl compounds, having an enone framework in their molecules Δ4-androstene-3,17-dione (11a) and Δ4-progestene-3,20-dione (11b) were reduced by 1 to 17-hydroxy-Δ4-androsten-3-one (12a) and 20-hydroxy-Δ4-progest-3-one (12b), which are essential human hormones, in 80percent and 67percent yields, respectively.
UTILISATION DES METHODES BIOLOGIQUES POUR LA PREPARATION DE SYNTHONS CHIRAUX : I-REDUCTION DE β-DICETONES ACYCLIQUES PAR SACCHAROMYCES CEREVISIAE (LEVURE DE BOULANGER)
Bolte, Jean,Gourcy, Jean-Gabriel,Veschambre, Henri
, p. 565 - 568 (2007/10/02)
The reduction of acyclic β-diketones by baker's yeast gave ketols, in many cases with high optical purity.The reaction is easy to carry out and provides chiral molecules of high synthetic interest.
Stereochemistry of 2,3-Dimethyl Analogues of the Reversed Ester of Pethidine and Related Compounds: Examples of Vicinal Diaxial Methyl Groups in 2,3-Dimethylpiperidine Derivatives
Casy, Alan F.,Ogungbamila, Francis O.,Rostron, Christopher
, p. 749 - 754 (2007/10/02)
The configurations and preferred solute conformations of three diastereomeric forms of 1,2,3-trimethyl-4-phenyl-piperidin-4-ol, isolated from the product of reaction between 1,2,3-trimethyl-4-piperidone and phenyl-lithium, are established from n.m.r. and other data as α, c-2-Me, c-3-Me,r-4-OH; β, t-2-Me,c-3-Me,r-4-OH (both eq-4-Ph chairs), and γ,c-2-Me,t-3-Me,r-4-OH (boat in CDCl3).Hydrochlorides of all three isomeric forms of corresponding acetates and propionates have preferred eq-4-Ph-chair conformation in CDCl3.In case of the γ-ester and γ-piperidin-4-ol hydrochlorides and the γ-piperidin-4-ol base in (CD3)2SO, avoidance of the 2,3-dimethyl γ-gauche interaction appears to be a determinant conformational factor.Isomeric potency rankings of the propionate esters in animal antinociceptive tests are γ>α>β.
Mevalonic acid analogs as inhibitors of cholesterol biosynthesis
DeBold,Elwood
, p. 1007 - 1010 (2007/10/02)
A series of 20 mevalonic acid analogs were synthesized and tested for their ability to inhibit cholesterol biosynthesis from [2-14C]-mevalonate in rat liver homogenates. Removal of the 5-hydroxyl group from mevalonic acid produced an active inhibitor, 3-hydroxy-3-methylpentanoic acid. Removal of the 3-hydroxyl group, addition of an aromatic group in the 3-position, or insertion of a double bond reduced inhibitory activity. Compounds with an aromatic group or halide on the 5-position were active inhibitors. The most active inhibitor was 5-phenylpentanoic acid, with 50% inhibition at 0.064 mM.
The Synthesis of Racemic 5-Hydroxy-3,4-dimethyl-1-hexene-2,5-dicarboxylic Acid (Senecivernic Acid)
Pastewka, Ulrich,Wiedenfeld, Helmut,Roeder, Erhard
, p. 785 - 790 (2007/10/02)
The synthesis of the title compound 10 is described.The structures of the intermediates were elucidated by IR, (1)H-NMR and mass spectrometry.
