81007-64-9Relevant academic research and scientific papers
Synthesis of treprostinil: Key claisen rearrangement and catalytic pauson-khand reactions in continuous flow
García-Lacuna, Jorge,Domínguez, Gema,Blanco-Urgoiti, Jaime,Pérez-Castells, Javier
, p. 9489 - 9501 (2019/11/14)
A new synthesis of treprostinil is described using a plug flow reactor in two of the key steps. First, a Claisen rearrangement reaction is described in scaled flow at multigram amounts. Yields and selectivity of this step are sharply improved compared to those from previous syntheses. Second, the key Pauson-Khand reaction in flow is described under catalytic conditions with 5 mol% of cobalt carbonyl and only 3 equiv. of CO. Scaling up of this reaction safely ensures a good yield of an advanced intermediate which is transformed into treprostinil in three steps. Other improvements are the introduction of the carboxymethyl chain into the phenol from the beginning to reduce the protection-deprotection steps. The synthesis is completed in 14% global yield after 12 linear steps from (S)-epichlorhydrin.
Total synthesis of natural (?)- and unnatural (+)-Melearoride A
Reed, Carson W.,Fulton, Mark G.,Nance, Kellie D.,Lindsley, Craig W.
supporting information, p. 743 - 745 (2019/02/09)
This communication details the first total synthesis of the 13-membered macrolide, (?)-Melearoride A, as well as unnatural (+)-Melearoride A. The synthesis features a concise 13 step synthesis (11 steps longest linear sequence) that offers flexible stereo-control and multiple opportunities for unnatural analog synthesis to delve into antifungal SAR. The route features a cuprate addition, an Evans asymmetric alkylation, and a ring-closing metathesis (RCM) to close the 13-membered macrocyclic core.
The curved front row neil intermediate preparation method
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Paragraph 0129; 0130; 0131; 0132, (2019/04/02)
The invention relates to a preparation method for a treprostinil intermediate (I). The preparation method comprises the steps that: a compound of a formula (II) and a compound of a formula (III) or acidic salt thereof react in the presence of a condensing agent to obtain a compound of a formula (IV); the compound of the formula (IV) and a compound of a formula (V) react to obtain a compound of a formula (I). According to the preparation method for the treprostinil intermediate, weinreb amide and alkyne negative ions react to directly obtain a ketone compound (I), so that environment pollution caused by heavy metal (a PCC oxidant) is avoided, and the adoption of a butyl lithium low-temperature reaction method is also avoided. The preparation method for the treprostinil intermediate has the advantages that reaction conditions are mild, the yield is high, the purity of products is high, and the industrial application prospect is wide. (Formulae (I), (II), (III), (IV) and (V) are shown in the specification)
Total Synthesis of Emmyguyacins A and B, Potential Fusion Inhibitors of Influenza Virus
Jana, Santanu,Sarpe, Vikram A.,Kulkarni, Suvarn S.
supporting information, p. 6938 - 6942 (2018/10/25)
Fungal glycolipids emmyguyacins A and B inhibit the pH-dependent conformational change of hemaglutinin A during replication of the Influenza virus. Herein, we report the first total synthesis and structure confirmation of emmyguyacins A and B. Our efficient route, which involves regioselective functionalization of trehalose, allows rapid access to adequate amounts of chemically pure emmyguyacin analogues including the desoxylate derivatives for SAR studies.
Total synthesis and biological evaluation of the cytotoxic resin glycosides ipomoeassin A-F and analogues
Nagano, Takashi,Pospisil, Jiri,Chollet, Guillaume,Schulthoff, Saskia,Hickmann, Volker,Moulin, Emilie,Herrmann, Jennifer,Mueller, Rolf,Fuerstner, Alois
supporting information; experimental part, p. 9697 - 9706 (2010/04/29)
A multitasking C-silylation strategy using the readily available compound 26 as a surrogate for cinnamic acid represents the key design element of a total synthesis of all known members of the ipomoeassin family of resin glyosides. This protecting group maneuver allows the unsaturated acids decorating the glucose subunit of the targets to be attached at an early phase of the synthesis, prevents their participation in the ruthenium-catalyzed ring-closing metathesis (RCM) used to form the macrocyclic ring, and protects them against reduc tion during the hydrogenation of the resulting cycloalkene over Wilkinson's catalyst. As the C-silyl group can be concomitantly removed with the O-TBS substituent using tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) in acetonitrile, no separate protecting group manipulations were necessary in the final stages, thus contributing to a favorable overall "economy of steps". In addition to the naturally occurring ipomoeassins, a small set of synthetic analogues has also been prepared by "diverted total synthesis". The cytotoxicity of these compounds was assayed with two different cancer cell lines. The recorded data confirm previous findings that the acylation- and oxygenation pattern of these amphiphilic glycoconjugates is highly correlated with their biological activity profile. Ipomoeassin F turned out to be the most promising member of the series, showing IC50 values in the low nanomolar range.
Method of preparation of an alkyne with an optically active hydroxyl group in the beta or gamma position of a triple bond and intermediates obtained
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Page/Page column 7, (2010/11/25)
The present invention relates to a method of preparation of an alkyne with an optically active hydroxyl group in the β or γ position of a triple bond and intermediates obtained. The method of the invention for preparation of an alkyne with an optically active hydroxyl group in the β position of a triple bond is characterized in that it comprises the reaction, in the presence of a Lewis acid: of a compound of formula (IV): in which: R is a linear or branched alkyl group having from 1 to 6 carbon atoms. and of a compound of formula (V): [in-line-formulae]R′—C≡C-M ??(V) [/in-line-formulae]in which: R′ represents a hydrogen atom, a linear or branched alkyl group having from 1 to 8 carbon atoms, preferably a methyl group or a trialkylsilyl group. M represents a metal, preferably a metal of group (Ia) of the periodic table, preferably lithium. Another object of the invention comprises the production of an alkyne with an optically active hydroxyl group in the γ position of a triple bond by isomerization of an alkyne with an optically active hydroxyl group in the β position previously obtained.
The Intramolecular Asymmetric Pauson-Khand Cyclization As A Novel and General Stereoselective Route to Benzindene Prostacyclins: Synthesis of UT-15 (Treprostinil)
Moriarty, Robert M.,Rani, Neena,Enache, Livia A.,Rao, Munagala S.,Batra, Hitesh,Guo, Liang,Penmasta, Raju A.,Staszewski, James P.,Tuladhar, Sudersan M.,Prakash, Om,Crich, David,Hirtopeanu, Anca,Gilardi, Richard
, p. 1890 - 1902 (2007/10/03)
A general and novel solution to the synthesis of biologically important stable analogues of prostacyclin PGI2, namely benzindene prostacyclins, has been achieved via the stereoselective intramolecular Pauson-Khand cyclization (PKC). This work illustrates for the first time the synthetic utility and reliability of the asymmetric PKC route for synthesis and subsequent manufacture of a complex drug substance on a multikilogram scale. The synthetic route surmounts issues of individual step stereoselectivity and scalability. The key step in the synthesis involves efficient stereoselection effected in the PKC of a benzoenyne under the agency of the benzylic OTBDMS group, which serves as a temporary stereodirecting group that is conveniently removed via benzylic hydrogenolysis concomitantly with the catalytic hydrogenation of the enone PKC product. Thus the benzylic chiral center dictates the subsequent stereochemistry of the stereogenic centers at three carbon atoms (C3a, C9a, and C1).
A Systematic Study on the Bakers'Yeast Reduction of 2-Oxoalkyl Benzoates and 1-Chloro-2-alkanones
Sakai, Takashi,Wada, Kou,Murakami, Takahiko,Kohra, Kiichiro,Imajo, Norihisa,et al.
, p. 631 - 638 (2007/10/02)
The bakers' yeast reduction of a series of 2-oxoalkyl arenecarboxylates (1a-f) (R=CH3 to n-C6H13; X=H) and the phenyl-modified derivatives (1g-l) (R=n-C5H11, X=OH, CH3, F, Cl, Br, or I) as well as 1-chloro-2-alkanones R(C=O)CH2Cl (6a-f) (R=CH3 to n-C6H13) were systematically investigated.The substrate specificities, configuration and percentee of the reduction products were found to be highly dependent on the length of the alkyl group (R) and the α substituent.Thus, the benzoates 1a-f gave optically active 2-hydroxyalkyl benzoates (2a-f) (R, configuration, percentee) (a: CH3, S, 99; b: C2H5, S, 98; c: C3H7, S, 26; d: n-C4H9, R, 55; e: n-C5H11, S, 15; f: n-C6H13, S, 63) in 11-91percent yields.Among the modification experiments of the phenyl group, 1g-l, the p-iodo substituent markedly increased the ee from 15 to 71percent, although the yield was rather lowered (22percent yield).The reduction of α-chloro ketones 6a-f also gave optically active 1-chloro-2-alkanols (7a-f) in 16-69percent yields.
