- Stereoselective total synthesis of (±)-vindeburnol and (±)-16-epi-vindeburnol
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A concise stereoselective total synthesis of (±)-vindeburnol and its epimer (±)-16-epi-vindeburnol is presented. This synthetic work features the utilization of Baeyer-Villiger oxidation to install different types of lactone substrate, and a sequence of a
- Chen, Fener,Chen, Xiangtao,Tang, Pei,Wang, Huijing,Yu, Lei,Zhang, Wen
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supporting information
p. 11669 - 11672
(2021/11/12)
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- Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
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The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
- Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
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supporting information
p. 7804 - 7808
(2019/10/14)
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- FURANONE COMPOUNDS AND METHODS OF MAKING AND USING THE SAME
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The invention features compounds of the general Formula (I): (formula should be inserted here) Compounds of Formula (I) possess unexpectedly high affinity for Alk5 and/or Alk4, and can be useful as antagonists thereof for preventing and/or treating numerous diseases, including fibrotic disorders.
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Page/Page column 50
(2008/12/07)
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- COMPOUND CONTAINING BASIC GROUP AND USE THEREOF
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The present invention relates to a compound represented by formula (I): wherein all symbols are as defined here, a salt thereof, a solvate thereof, or a prodrug thereof. The compound of the present invention has an antagonistic activity against CXCR4 and is therefore useful as a preventive and/or therapeutic agent for CXCR4-mediated diseases, for example, inflammatory and immune diseases (for example, rheumatoid arthritis, arthritis, retinopathy, pulmonary fibrosis, rejection of transplanted organ, etc.), allergic diseases, infections (for example, human immunodeficiency virus infection, acquired immunodeficiency syndrome, etc.), psychoneurotic diseases, cerebral diseases, cardiovascular disease, metabolic diseases, and cancerous diseases (for example, cancer, cancer metastasis, etc.), or an agent for regeneration therapy.
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Page/Page column 79-80
(2008/12/06)
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- Improvement of a stereoselective biocatalytic synthesis by substrate and enzyme engineering: 2-hydroxy-(4×-oxocyclohexyl)acetonitrile as the model
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Even if biocatalysis is finding increasing application, it still has to gain widespread use in synthetic chemistry. Reasons for this are limitations that enzymes have with regard to substrate range, reaction scope, and insufficient selectivity with unnatural compounds. These shortcomings can be challenged by enzyme and/or substrate engineering, which are employed to alter substrate specificity and enhance the enzyme selectivity toward unnatural substrates. Herein, these two approaches are coupled to improve the hydroxynitrile lyase catalyzed synthesis of 2-hydroxy-(4′-oxocyclohexyl) acetonitrile (4). The ketone functionality is masked as an enol ether, and the oxynitrilase of Hevea brasiliensis is engineered towards this masked substrate to give the product with a high optical purity and to drastically lower the amount of enzyme needed.
- Avi, Manuela,Wiedner, Romana M.,Griengl, Herfried,Schwab, Helmut
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experimental part
p. 11415 - 11422
(2009/10/17)
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- Synthesis and biological activities of tetrahydroquinazoline analogs of aminopterin and methotrexate
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(6R,6S)-5,8-Dideaza-5,6,7,8-tetrahydroaminopterin (1) and (6R,6S)-5,8-dideaza-5,6,7,8-tetrahydromethotrexate (2) were synthesized as potential inhibitors of dihydrofolate reductase (DHFR) and as antitumor agents. Cyclohexanone-4-carboxaldehyde dimethyl acetal, a key intermediate was synthesized from cyclohexane-1,4-dione monoethylene ketal, which was converted via a Wittig reaction to its exocyclic 4-methylene derivative which in turn, was converted to the 4-aldehyde via a hydroboration-oxidation sequence. Selective protection of the 4-aldehyde as the dimethylacetal and cyclization with dicyandiamide afforded the 6-dimethylacetal of 2,4-diamino-5,6,7,8-tetrahydroquinazoline. Protection of the 2,4-diamino moieties and selective deprotection of the 6-aldehyde followed by reductive amination with p-aminobenzoyl-L-glutamate afforded 2,4-bisacetamido-5,8-dideaza-5,6,7,8-tetrahydroaminopterin (11). Deprotection of 11 afforded 1. Compound 2 was obtained from 11 via N10-methylation and deprotection. The N10-methyl analogue 2 was 2-10 fold more potent than 1 as an inhibitor of various DHFRs. In the in vitro preclinical screening program of the National Cancer Institute, compound 2 inhibited the growth of eighteen of the twenty nine tumor cell lines in culture at a GI50 -8 M.
- Gangjee,Zaveri,Queener,Kisliuk
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p. 243 - 247
(2007/10/02)
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- Liquid crystals
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Compounds of the formula STR1 wherein n stands for the number 0 or 1; the rings A1, A2 and A3 represent 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also represents a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; X1 represents a single covalent bond, --COO--, --OOC--, --CH2 CH2 --, p--C6 H4 --, --CH2 CH2 --p-- C6 H4 --, --CH2 CH2 --p--C6 H4 --CH2 CH2 -- or, insofar as the rings A1 and A2 represent 1,4-phenylene, also --NON--; R2 represents 1E-alkenyl, 2Z-alkenyl, 3E-alkenyl, 4-alkenyl or alkenyloxy, with the proviso that the oxygen atom in alkenyloxy is linked with a saturated carbon atom; and R1 signifies 1E-alkenyl, 2Z-alkenyl, 3E-alkenyl, 4-alkenyl or, insofar as R2 represents alkenyloxy, also alkyl, their manufacture, as well as liquid crystalline mixtures and the use for electro-optical purposes.
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- Liquid crystalline compounds and mixtures
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This invention concerns compounds of the formula: STR1 wherein X is a single covalent bond, --CH2 CH2 --, 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a group of the formula: STR2 ring A is trans-1,4-cyclohexylene or, when X is a single covalent bond, ring A may also be 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; and R1 is straight-chain trans-1-alkenyl having 2 to 12 carbon atoms or straight-chain trans-3-alkenyl having 4 to 12 carbon atoms or, when X is --CH2 CH2 --, R1 may also be 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a group of formula IA or when ring A is a 2,5-disubstituted pyrimidine ring or a trans-2, 5-disubstituted m-dioxane ring, R1 may also be straight-chain alkyl with 1 to 12 carbon atoms; and one of the benzene rings may have a lateral fluorine substituent; their manufacture, and liquid crystalline mixtures and electro-optical devices containing same.
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- CHEMISTRY OF ENOL ETHERS. LXXXVI. DIENE CONDENSATION OF 2-TRIMETHYLSILYLOXY-1,3-DIENES WITH α,β-UNSATURATED ALDEHYDES. 1-FORMYL-4-TRIMETHYLSILYLOXY-3-CYCLOHEXENES AND 1-FORMYL-4-OXOCYCLOHEXANES
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The diene condensation of a series of 2-trimethylsilyloxy-1,3-dienes (2-trimethylsilyloxy-1,3-butadiene, 2-trimethylsilyloxy-1,3-pentadiene, 2-trimethylsilyloxy-4-methyl-1,3-pentadiene) with acrylaldehyde and crotonaldehyde is distinguished by high regioselectivity and low stereoselectivity.The "para" adducts (1-formyl-4-trimethylsilyloxy-3-cyclohexenes) are formed exclusively in all cases, and the reaction leads to the formation of a mixture of the cis and trans isomers with respect to the asymmetric centers.Alcoholysis or acid hydrolysis of 1-formyl-4-trimethylsilyloxy-3-cyclohexenes give high yields of 1-formyl-4-oxocyclohexanes.In a number of cases the diene condensation is accompanied by the formation of undesirable side compounds, produced as a result of transsilylation, which takes place between the 2-trimethylsilyloxy-1,3-diene and crotonaldehyde used in the reaction.
- Makin, S. M.,Shavrygina, O. A.,Nguyen, Fong Tung
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p. 2082 - 2087
(2007/10/02)
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- Novel liquid crystal mixtures
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Liquid crystalline mixtures containing compounds of the formula STR1 wherein n stands for the number 0 or 1; X1 and X2 denote single covalent bonds or one of the symbols X1 and X2 also denotes --COO--, --OOC-- or --CH2 CH2 --; the rings A1, A2 and A3 represent 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also represents a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; R1 signifies 4-alkenyl or on a cyclohexyl ring also 2Z-alkenyl; and R2 denotes alkyl, alkoxy, --CN or --NCS, as well as the manufacture of these compounds and the use for electro-optical purposes are described.
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- Liquid crystals
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Compounds of the formula STR1 wherein R1 is hydrogen or straight-chain alkyl; R2 is --CN, --R, --COR, --COOR or when R2 is positioned on an aromatic ring R2 also can be --OR, --OOCR or --F; R is alkyl; A is a group with 1 to 4 six-membered rings, these rings being linked directly with one another and with ring B in each case via a single covalent bond or being linked at one or two positions also via --COO--, --OOC-- or --CH2 CH2 --; the six-membered rings in A and ring B each are 1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also is trans-2,5-disubstituted m-dioxane, 2,5-disubstituted pyrimidine or 3,6-disubstituted pyridazine, with the proviso that a maximum of two adjacent trans-1,4-cyclohexylene rings are linked directly via a single covalent bond; and m is the integer 2, or when ring B is trans-1,4-cyclohexylene or trans-2,5-disubstituted m-dioxane, m also can be the integer 0, their manufacture, liquid crystalline mixtures which contain these compounds as well as the use of these compounds for electro-optical purposes are described. Additionally, compounds of the formula STR2 wherein R8 is straight-chain C1 -C12 alkyl, their manufacture, liquid crystalline mixtures which contain these compounds and their use for electro-optical purposes are described.
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- New Liquid Crystals: The Synthesis and Mesomorphic Properties of Alkenylsubstituted Cyanophenylethylcyclohexanes and Cyanobiphenylylcyclohexanes
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Nineteen alkenylsubstituted cyanophenylethylcyclohexanes and cyanobiphenylylcyclohexanes have been synthesized by systematically varying both the position and the configuration of the isolated C,C-double bond.The influences of such structural changes on the mesomorphic properties are discussed and the observed nematic thermal stabilities (cf.Table I) are compared, where possible, with those of the corresponding saturated alkyl analogs.
- Petrzilka, Martin,Germann, Alfred
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p. 327 - 342
(2007/10/02)
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