212051-35-9Relevant academic research and scientific papers
Total Synthesis of Disciformycin A and B: Unusually Exigent Targets of Biological Significance
Kwon, Yonghoon,Schulthoff, Saskia,Dao, Quang Minh,Wirtz, Conny,Fürstner, Alois
, p. 109 - 114 (2018)
The first total synthesis of the potent antibiotic disciformycin B (2) is described, which is exceptionally isomerization-prone and transforms into disciformycin A (1) even under notably mild conditions. To outweigh this bias, the approach to 2 hinged on
Preparation of Alkyl Ethers with Diallyltriazinedione-Type Alkylating Agents (ATTACKs-R) Under Acid Catalysis
Fujita, Hikaru,Yamashita, Rina,Fujii, Takanori,Yamada, Kohei,Kitamura, Masanori,Kunishima, Munetaka
, p. 4436 - 4446 (2019/07/03)
Diallyltriazinedione-type acid-catalyzed alkylating agents (ATTACKs-R) with 10 different alkyl groups (R), including benzyl, substituted benzyl, allyl, and methyl groups were synthesized. The palladium-catalyzed intramolecular O-to-N allylic rearrangement of 2,4-bis(allyloxy)-6-chloro-1,3,5-triazine was developed to introduce various alkoxy groups into the N,N′-dialkylated triazinedione skeleton. O-Alkylation of alcohols with ATTACKs-R was carried out in 1,4-dioxane in the presence of 2,6-di-tert-butylpyridinium trifluoromethanesulfonate or trifluoromethanesulfonic acid as a catalyst. Six selected ATTACKs-R bearing benzylic R groups were employed to prepare alkyl ethers from primary, secondary, and tertiary alcohols. The reactions of ATTACKs-R bearing an o-nitro-substituted benzyl group tended to afford low yields. Comparison of four different triazinedione-based benzylating reagents suggested that the N,N′-substituents affected the reactivity.
PROCESS FOR THE PREPARATION OF MACROCYCLIC KETONE ANALOGS OF HALICHONDRIN B
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Page/Page column 41-42, (2019/11/19)
The present invention discloses a novel process for the preparation of macrocyclic ketone analogs of halichondrin B or pharmaceutically acceptable salts thereof and to novel intermediates which are produced during the course of carrying out the novel process.
Polyoxygenated Tertiary Alcohols: A Kiyooka Approach
Lücke, Daniel,Kalesse, Markus
supporting information, p. 10080 - 10083 (2019/07/18)
A Kiyooka aldol approach for the stereoselective synthesis of tertiary alcohols is presented. This approach allows for the incorporation of different substituents at all three remaining positions at the chiral center bearing the tertiary alcohol. To demon
Nhatrangin A: Total Syntheses of the Proposed Structure and Six of Its Diastereoisomers
Dias, Luiz C.,Polo, Ellen C.
, p. 4072 - 4112 (2017/04/28)
A total synthesis of the proposed structure of nhatrangin A is described. This strategy relies on two aldol reactions to install the chiral centers at C3/C4 and C3′/C4′, a lithium-mediated coupling between an advanced intermediate alkyne and a Weinreb amide to complete the C1-C13 alkyl scaffold, and a Yamaguchi esterification to set the side chain. Discrepancies in the spectroscopic data between synthetic and natural nhatrangins led us to synthesize six more diastereoisomers of the proposed structure of nhatrangin A.
Towards the total synthesis of the anti-trypanosomal macrolide, Actinoallolides: Construction of a key linear intermediate
Oshita, Jun,Noguchi, Yoshihiko,Watanabe, Akito,Sennari, Goh,Sato, Shogo,Hirose, Tomoyasu,Oikawa, Daiki,Inahashi, Yuki,Iwatsuki, Masato,Ishiyama, Aki,Omura, Satoshi,Sunazuka, Toshiaki
supporting information, p. 357 - 360 (2016/01/12)
Herein, we describe the synthesis of key intermediate (+)-8 as an essential intermediate including full carbon framework for completing the convergent total synthesis of Actinoallolide A (1). (+)-8 was obtained by Negishi and Stille cross coupling from (+)-9, (+)-10 and (-)-11. Stereo-divergent preparation of two similar units, consisting of three consecutive stereocenters, facilitated the synthesis of (+)-10 and (-)-11.
Directed hydrogenations and an Ireland-Claisen rearrangement linked to Evans-Tishchenko chemistry: The highly efficient total synthesis of the marine cyclodepsipeptide doliculide
Chen, Tao,Altmann, Karl-Heinz
supporting information, p. 8403 - 8407 (2015/06/02)
Two new convergent total syntheses have been developed for the cytotoxic, actin microfilament-stabilizing marine cyclodepsipeptide doliculide (1). A key strategic element of both routes is the establishment of the central stereogenic center of the characteristic polydeoxypropionate stereotriad by means of a hydroxyl-directed catalytic hydrogenation of a trisubstituted double bond. The requisite olefin substrates were obtained through a modified Suzuki-Miyaura coupling or through Ireland-Claisen rearrangement of a propionate ester, respectively; the latter was the direct result of a highly selective Evans-Tishchenko reduction of a hydroxy ketone that had been obtained in a stereoselective Paterson aldol reaction. Doliculide (1) was finally obtained in a total number of 17 or 15 (14) linear steps, respectively, which represents a substantial improvement over previous syntheses of this highly bioactive natural product.
Concise diastereoselective synthesis of calcaripeptide C via asymmetric transfer hydrogenation/Pd-induced chiral allenylzinc as a key reaction
Kumaraswamy, Gullapalli,Narayanarao, Vykunthapu,Raju, Ragam
supporting information, p. 8487 - 8494 (2015/08/06)
Synthesis of the natural product calcaripeptide C derived from the fungal metabolite mycelium KF525 of Calcarisporium sp. has been achieved. This complementary approach avoids the use of a stoichiometric amount of chiral auxiliary reagents as commonly used to generate enantioenriched advanced precursors. The enantioselective synthesis of calcaripeptide C is remarkable in that using catalytic reactions sets the two stereogenic centers efficiently with good levels of enantioselectivity. Further diversification of the calcaripeptide C structures is possible by employing a complementary catalytic enantioenriched Ru-catalyst.
Chemoselective formation of unsymmetrically substituted ethers from catalytic reductive coupling of aldehydes and ketones with alcohols in aqueous solution
Kalutharage, Nishantha,Yi, Chae S.
supporting information, p. 1778 - 1781 (2015/04/14)
A well-defined cationic Ru-H complex catalyzes reductive etherification of aldehydes and ketones with alcohols. The catalytic method employs environmentally benign water as the solvent and cheaply available molecular hydrogen as the reducing agent to afford unsymmetrical ethers in a highly chemoselective manner.
Synthetic studies towards an advanced precursor of the jatrophane diterpene Pl-4
Fürst, Rita,Lentsch, Christoph,Rinner, Uwe
supporting information, p. 357 - 367 (2014/02/14)
Jatrophane diterpenes, isolated from members of the Euphorbiaceae plant family, constitute a class of biologically and structurally intriguing natural products. Herein, different strategies for the preparation of an advanced intermediate towards the total synthesis of the jatrophane diterpene Pl-4 are described. Key strategies for the elaboration of the jatrophane precursors include hydrometalation and radical reactions. Georg Thieme Verlag KG Stuttgart · New York.
