- Method for preparing silicon compounds
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The invention provides a method for preparing silicon compounds, and belongs to the field of chemical synthesis. The method for preparing the silicon compounds comprises the following processes that citric acid is used as a raw material for performing oxidative decarboxylation to obtain a compound 1,3-acetone dicarboxylic acid; esterification reaction is carried out to obtain a compound 1,3-acetone dicarboxylic acid dimethyl ester; catalytic hydrogenation reduction is carried out to obtain a compound 3-hydroxyglutaric acid dimethyl ester; etherification reaction is carried out to obtain a compound3-tertiary butyl dimethyl siloxy dimethyl glutarate; saponification, dehydration and purification are carried out to obtain 3-tert-butyl-dimethylsiloxyglutaric anhydride; and a catalyst for catalytic hydrogenation is Cu/ZnO/Al2O3 prepared by a precipitation reduction method. According to the method for preparing the silicon compounds, the catalyst for catalytic hydrogenation is optimized, so that in the hydrogenation reduction reaction, the hydrogenation activity of a Cu catalyst is significantly improved, the selectivity is increased, and the generation of by-products is reduced; and theproduct yield and purity are significantly improved by recrystallization with a mixed solvent.
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- Preparation method of high-purity statin drug intermediate
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The invention relates to a preparation method of a high-purity statin drug intermediate. The preparation method is characterized in that 3-hydroxyl ethyl glutarate is used as the initial raw material to prepare (3R)-tert-butyl dimethyl silyloxy-5-oxo-6-triphenyl phosphine caproate (abbreviated as J6) through substitution reaction, hydrolysis reaction, cyclization reaction, resolution reaction, hydrogenation reaction, acylation reaction and Wittig reaction. The preparation method is mild in condition, stable in process, cheap in raw material, easy in raw material obtaining, easy in three-waste treatment, low in preparation cost, high in product purity and suitable for industrial production.
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Paragraph 0018; 0030
(2017/09/01)
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- Synthesis of GABOB and GABOB-based chiral units possessing distinct protecting groups
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In addition to the varied biological activity of GABOB (4-amino-3- hydroxybutanoic acid), the structure of its protected derivatives makes them interesting chiral intermediates for the synthesis of more complex compounds. A stereoselective route to GABOB derivatives with three different protecting groups is presented, using anhydride desymmetrization as a chirality-inducing step. Selective removal of the protecting groups gave compounds with a free carboxylic acid or hydroxy group. Removal of all of the protecting groups allowed GABOB to be isolated in good yield and with excellent ee. A stereoselective route to GABOB (4-amino-3-hydroxybutanoic acid) derivatives with three different protecting groups is presented. Selective deprotection produced diprotected chiral building blocks with a free carboxylic acid or hydroxy group. Removal of all the protecting groups allowed GABOB to be isolated. Copyright
- Ivsic, Trpimir,Dokli, Irena,Rimac, Ana,Hamersak, Zdenko
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p. 631 - 638
(2014/02/14)
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- Synthesis of GABOB and GABOB-Based Chiral Units Possessing Distinct Protecting Groups
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In addition to the varied biological activity of GABOB (4-amino-3-hydroxybutanoic acid), the structure of its protected derivatives makes them interesting chiral intermediates for the synthesis of more complex compounds. A stereoselective route to GABOB derivatives with three different protecting groups is presented, using anhydride desymmetrization as a chirality-inducing step. Selective removal of the protecting groups gave compounds with a free carboxylic acid or hydroxy group. Removal of all of the protecting groups allowed GABOB to be isolated in good yield and with excellent ee.
- Ivic, Trpimir,Dokli, Irena,Rimac, Ana,Hamerak, Zdenko
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p. 631 - 638
(2015/10/05)
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- 2-PYRROLIDONE SUBSTITUTED DIHYDROXY ALKANOIC, ALKENOIC AND ALKYNOIC ACIDS, COMPOSITIONS AND HMG-COA REDUCTASE INHIBITION THEREWITH
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Antihypercholesterolemic activity has been discovered in compounds of the formula and pharmaceutically acceptable salts thereof, wherein: Z is X is lower alkyl, lower alkenyl, or lower alkenyl; R1 is hydrogen, alkyl, alkenyl, aryl, alkylaryl, or substituted aryl having one or more substituents; and one of R2 and R3 is hydrogen and the other is hydrogen, alkyl, alkenyl, aryl, alkylaryl or alkenyl aryl; or R2 and R3 are both lower alkyl; or R2 and R3 together complete a substituted or unsubstituted hydrocarbon ring that is cycloalkyl or cycloalkenyl with substituents as defined in the specification.
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- Process for preparing a keto-phosphonate intermediate useful in preparing HMG-CoA reductase inhibitors
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A process is provided for preparing the keto-phosphonate STR1 in enantiomerically homogeneous form, by reacting the anhydride STR2 with S-α-methylbenzylamine to effect diastereoselective opening of the anhydride to give a mixture of amides STR3 separating the amides, for example, by frictional crystallization, and converting the desired amide IVA (which is obtained in high yield from the anhydride) to enantiomerically homogeneous ketophosphonate in high yield and on a large scale. The so-formed ketophosphonate is useful in the synthesis of compactin as well as 7-substituted-(3,5-dihydroxy)-hept-6-enoic and -heptanoic acid HMG-CoA reductase inhibitors.
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- Total Synthesis and Biological Evaluation of Structural Analogues of Compactin and Dihydromevinolin
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The full experimetal details for the total synthesis of (+)-compactin and 19 structural analogues are reported.We have evaluated three classes of analogues as inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase: (1) functional and stereoisomeric analogues that posses the full carbon skeleton of compactin or dihydromevinolin, (2) functional analogues in which one carbon of the skeleton has been replaced by oxygen, and (3) analogues in which all of the 3,5-dihydroxyvaleric acid moiety has been omitted.Our most potent inhibitors belong to the first class of analogues.Compounds 42 (5-ketocompactin) and 69 (5-ketodihydromevinolin) are as active as the natural products compactin and dihydromevinolin, respectively (I50 = 1-20 nM).The corresponding enones 37 and 68 are less active, having I50 values 20-30 times larger.Inverting the stereochemistry at C-3 or C-5 or about the hexahydronaphthalene ring of compactin results in the elevation of the I50 to values in the micromolar range, comparable to the KM of the natural substrate 3-hydroxy-3-methylglutaryl coenzyme A.Class 2 analogues are active in this concentration range also.The synthetic sequence developed for compactin and its analogues includes a new method that permits the selective preparation of either the R or the S epimer at C-3 of the 3,5-dihydroxyvaleric acid moiety.This entails the reaction of anhydride 9 with either (R)- or (S)-1-phenylethanol in the presence of 4-(N,N-dimethylamino)pyridine and triethylamine.The prochiral recognition is surprisingly high; under optimum conditions, the reaction of 9 with (R)-1-phenylethanol leads to a 15:1 ratio of diesters 17 and 18.
- Heathcock, Clayton H.,Hadley, Cheri R.,Rosen, Terry,Theisen, Peter D.,Hecker, Scott J.
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p. 1858 - 1873
(2007/10/02)
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- Mimics of Transaminase Enzymes
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Pyridoxamine has been attached to the primary side and to the secondary side of β-cyclodextrin; the resulting compounds convert α-keto acids to amino acids with substrate selectivity and some stereoselectivity.Pyridoxamine has also been attached to a synthetic macrocycle; the attached binding group showed substrate selectivity.Chains carrying catalytic basic groups have been attached to pyridoxamine; appropriate systems catalyze the prototropic rearrangement characteristic of transamination.A catalyzed HCl elimination involving chloropyruvic acid was observed.A tetrahydroquinoline system related to pyridoxamine was synthesized to permit the stereochemically defined placement of a basis catalytic group.This converted keto acids to amino acids with good stereoselectivity for the formation of optically active products.
- Breslow, R.,Czarnik, A. W.,Lauer, M.,Leppkes, R.,Winkler, J.,Zimmerman, S.
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p. 1969 - 1979
(2007/10/02)
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