- A synthetic approach to 5/5/6-polycyclic tetramate macrolactams of the discodermide type
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A flexible synthetic route to the 16-membered tetramate-embedding macrocyclic scaffold present in various polycyclic tetramate macrolactams (PTMs) was developed which differs from the seminal synthesis of ikarugamycin by Boeckman Jr. in protecting groups and the order of connections. We also devised a short approach to various stereoisomers of the 5/5/6-tricarbocyclic motif found in discodermide and other PTMs, starting from the Weiss’ diketone.
- Bodenschatz, Kevin,St?ckl, Julia,Winterer, Markus,Schobert, Rainer
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- Solvent free synthesis of 1-alkoxyphosphonium chlorides for stereoselective multipurpose vinyl ethers
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An efficient solvent free method is developed for the preparation of structurally diverse 1-alkoxymethylphosphonium chlorides in high yield. One of the prepared salts derived from (1 R,2S,5R)-(?)-Menthol auxiliary was further employed for the synthesis of vinyl ethers, where up to 99% stereoselectivity was achieved.
- Cheema, Zain Maqsood,Gondal, Humaira Yasmeen,Siddiqui, Hina,Choudhary, Muhammad Iqbal
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- Preparation method of 2-cyclopropyl propanal
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The invention relates to the field of organic synthesis, in particular to a synthesis method of 2-cyclopropyl propanal. According to the method, methoxy methyl triphenyl phosphonium chloride is reacted with cyclopropyl methyl ketone under the action of a base to generate 1-methoxy-2-cyclopropyl propanal; and the 1-methoxy-2-cyclopropyl propanal undergoes acidification and hydrolysis form the 2-cyclopropyl propanal. The synthesized 2-cyclopropyl propanal is calculated by cyclopropyl methyl ketone, has a yield which is more than 95%, and has the advantages of being less in by-products, high in yield and low in cost.
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Paragraph 0022; 0025
(2019/04/06)
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- Berberine derivative and use thereof
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The invention discloses a berberine derivative for treating bacterium infection, and a use for thereof. The berberine derivative has a structure shown in the description. Experiments prove that the berberine derivative has positive ion charges under physiological conditions, and has the characteristics of broad antibacterial spectrum, good biocompatibility, good water solubility, strong targetingand low toxicity, a preparation method has the advantages of simplicity, easiness in implementing, high yield, and significant curative effect in the antibacterial field.
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Paragraph 0042; 0087-0088
(2018/06/15)
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- A (methoxy methyl) trityl chloride synthesis method (by machine translation)
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The invention relates to the field of chemical synthesis, in particular to a (methoxy methyl) trityl chloride synthesis method, comprises the following steps: under the protection of nitrogen, is added to the reactor solvent anhydrous acetone, then adding triphenylphosphine, to side edge which temperature rises to 36 - 38 °C, maintain a constant temperature, the methyl ether is added to the reactor, after the 36 - 38 °C lower reaction 3h, the temperature slowly increased to 46 - 48 °C, continue to reaction 3h, stopping the reaction, filtration, anhydrous ethyl ether washing, drying, to obtain (methoxy methyl) trityl chloride; this invention synthetic (a ethoxymethyl) trityl chloride high yield, purity is good, the synthetic method is simple, easy to control, is suitable for popularization and application. (by machine translation)
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Paragraph 0008; 0017; 0018; 0019; 0020; 0021; 0022-0025
(2017/08/28)
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- A formal synthesis of (±)-cephalotaxine via pauson-khand reaction
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A concise route toward the formal synthesis of (±)-cephalotaxine has been developed. An intermolecular Pauson-Khand reaction was adopted to construct the cyclopentenone ring efficiently with high regioselectivity. Georg Thieme Verlag Stuttgart. New York.
- Xing, Ping,Huang, Zuo-Gang,Jin, Yun,Jiang, Biao
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p. 596 - 600
(2013/04/10)
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- Chemoselective halogenation of 2-hydroperfluoroalkyl aldehydes
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2-Hydroaldehydes, RfCH(R)CHO, where Rf = CF 3, C2F5, n-C3F7 and R = CF3, C2F5, n-C3F7, Ph, H, were prepared via acid hydrolysis of the corresponding vinyl ethers, R fC(R) = CHOCH3, which can be readily prepared by reaction of Ph3P+C?HOCH3 with the corresponding ketone. The 2-hydroaldehydes can be chemoselectively converted to the acyl halide, RfCH(R)C(O)X (X = Cl, Br), via free-radical halogenation. The perfluoroalkyl group deactivates the 2-position toward radical abstraction of the 2-hydrogen, and halogenation occurs exclusively at the formyl hydrogen. However, halogenations of the 2-hydroaldehydes in glacial acetic acid chemoselectively gives the 2-haloaldehydes, RfCX(R)CHO, X = Cl, Br. Hydrolysis of the 2-hydroperfluoroacyl halides provides a useful route to 2-hydroperfluoroalkyl branched carboxylic acids, useful ketene precursors. This route avoids the use of toxic fluoroolefins, such as perfluoroisobutylene.
- Wiebe, Donald A.,Burton, Donald J.
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experimental part
p. 4 - 11
(2012/07/13)
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- Syntheses of oxidized metabolites implicated as active forms of the highly potent carcinogenic hydrocarbon dibenzo[def,p]chrysene
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Polycyclic aromatic hydrocarbons (PAHs) are an important class of environmental carcinogens, and dibenzo[def,p]chrysene is the most potent carcinogenic PAH currently known. Syntheses of various oxidized metabolites of dibenzo[def,p]chrysene implicated as the biologically active forms that interact directly or indirectly with DNA to induce mutations that lead to tumor induction are reported. These include the 8,9- and 11,12-dihydrodiols (2 and 3), the 8,9,11,12-bis-dihydrodiol (5), and the fjord region anti-diol epoxide derivative of 3 (4).
- Zhang,Harvey
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p. 625 - 636
(2007/10/03)
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- The Preparation and 13C-NMR Spectra of Alkoxymethyl-triphenylphosphonium Salts
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Alkoxymethyltriphenylphosphonium salts, X, X: Cl, Br, and I, R: CH3, C2H5, and i-C3H7, have been obtained from the reaction of the triphenylphosphine and the corresponding alkyl halomethyl ether.In the 13C-NMR spectra of these salts, the coupling constant (JCP) is 68-71 Hz, which is larger than that (JCP: 48-56 Hz) of Br,R:H,CH3, and i-C3H7, Me3P=S and Me3P=Se, while it is close to that(66-69Hz) of Me3P=O and Et3P=O.The coupling constant (JCP) of these salts can be caused by the oxygen atom in the salts.
- Yamamoto, Yoshihisa,Kanda, Zenjiro
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p. 3436 - 3438
(2007/10/02)
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- Novel steroids of the oestrane series substituted in 7-position
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The invention relates to novel 7-substituted-steroids of the oestrane series of the general formula: SPC1In whichRing A including carbon atom 6 is SPC2R 1 = an alkyl group with 1-4 C-atoms,R 2 = oxygen or (αY)(βZ), in which Y = hydrogen or a saturated or unsaturated alkyl group with 1-4 C-atoms and Z = a free, esterified or etherified hydroxyl group,R 3 = hydrogen or a free or esterified hydroxyl group,R 4 = an alkylene- or alkylidene group with 1-3 C-atoms,R 5 = hydrogen or a free, esterified or etherified hydroxyl group,R 6 = H 2, O, H(OH), H(Oalkyl) or H(Oacyl),X = H, an acyl group or an alkyl-, aralkyl-, cycloalkyl- or heterocyclic alkyl group, andA double bond is present starting from carbon atom 5, and to processes for their preparation.These novel steroids possess anabolic, androgenic, oestrogenic, progestative, ovulation-inhibiting and gonad-inhibiting properties.
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