160238-45-9Relevant articles and documents
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
, 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.
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.
Chemoenzymatic asymmetric total synthesis of nonanolide (Z)-cytospolides D, E and their stereoisomers
Rej, Rohan Kalyan,Nanda, Samik
, p. 860 - 871 (2014/03/21)
Chemoenzymatic asymmetric total synthesis of the (Z)-isomer of the naturally occurring decanolide cytospolides D, E and six stereoisomers is reported. The main highlight of the synthetic venture involves ring-closing metathesis (RCM) reaction of a suitably functionalized ester compound, which was assembled by the Yamaguchi coupling of the required acid and alcohol fragments. The alcohol fragment was ac- cessed by two alternative chemoenzymatic processes, one being hydroxynitrile lyase mediated hydrocyanation, whereas lipase-catalyzed transesterification was the key sep in the second route. The acid fragment was constructed by an enantioselective enzymatic desymmetrization (EED) of prochiral 2-methyl-1,3-propanediol and Corey-Bakshi-Shibata (CBS) mediated stereoselective carbonyl reduction.
Prediction and determination of the stereochemistry of the 1,3,5-trimethyl-substituted alkyl chain in verucopeptin, a microbial metabolite
Yoshimura, Aya,Kishimoto, Shinji,Nishimura, Shinichi,Otsuka, Saori,Sakai, Yuki,Hattori, Akira,Kakeya, Hideaki
, p. 6858 - 6867 (2014/08/18)
For the prediction of the relative stereochemistry of 1,3-dimethyl substitution in alkyl chains, a simple approach based on 1H NMR data was recently proposed; Δδ values of methylene protons located between methyl-substituted methine carbons can
Synthetic studies towards an advanced precursor of the jatrophane diterpene Pl-4
Fürst, Rita,Lentsch, Christoph,Rinner, Uwe
, 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.
Chemoenzymatic Asymmetric Total Synthesis of Nonanolide (Z)-Cytospolides D, e and Their Stereoisomers
Rej, Rohan Kalyan,Nanda, Samik
, p. 860 - 871 (2015/10/05)
Chemoenzymatic asymmetric total synthesis of the (Z)-isomer of the naturally occurring decanolide cytospolides D, E and six stereoisomers is reported. The main highlight of the synthetic venture involves ring-closing metathesis (RCM) reaction of a suitably functionalized ester compound, which was assembled by the Yamaguchi coupling of the required acid and alcohol fragments. The alcohol fragment was accessed by two alternative chemoenzymatic processes, one being hydroxynitrile lyase mediated hydrocyanation, whereas lipase-catalyzed transesterification was the key sep in the second route. The acid fragment was constructed by an enantioselective enzymatic desymmetrization (EED) of prochiral 2-methyl-1,3-propanediol and Corey-Bakshi-Shibata (CBS) mediated stereoselective carbonyl reduction.
Synthesis of (+)-discodermolide by catalytic stereoselective borylation reactions
Yu, Zhiyong,Ely, Robert J.,Morken, James P.
supporting information, p. 9632 - 9636 (2014/10/15)
The marine natural product (+)-discodermolide was first isolated in 1990 and, to this day, remains a compelling synthesis target. Not only does the compound possess fascinating biological activity, but it also presents an opportunity to test current methods for chemical synthesis and provides an inspiration for new reaction development. A new synthesis of discodermolide employs a previously undisclosed stereoselective catalytic diene hydroboration and also establishes a strategy for the alkylation of chiral enolates. Furthermore, this synthesis of discodermolide provides the first examples of the asymmetric 1,4-diboration of dienes and borylative diene-aldehyde couplings in complex-molecule synthesis. Borylation-based synthesis: The development of a strategy for stereocontrol in catalytic diene hydroboration enables the synthesis of a critical building block for the assembly of (+)-discodermolide. Combined with asymmetric catalytic diboration, hydroformylation, and borylative aldehyde-diene coupling reactions, (+)-discodermolide could then be prepared from simple hydrocarbon-based building blocks.
Stereoselectivity of model C22-23 aldol coupling for spirangiens A & B
Gregg, Claire,Perkins, Michael V.
supporting information, p. 387 - 394 (2013/01/15)
A model system was prepared to investigate the diastereoselectivity of the key C22-23 aldol coupling for the synthesis of spirangiens A & B. The lithium enolate of model ketone 3 was coupled with the differently protected aldehydes 4 (acetonide) and 5 (silyl) giving 3:1 and 3.5:1 dr, respectively, in favour of the unnatural (S) isomer in both cases. The lack of any significant effect on the aldol stereoselectivity induced by the aldehyde protecting groups contrasts with previous literature reports.
Synthesis of an advanced intermediate of the jatrophane diterpene Pl-4: A dibromide coupling approach
Fuerst, Rita,Rinner, Uwe
, p. 8748 - 8758 (2013/09/24)
The preparation of an advanced intermediate toward the synthesis of the jatrophane diterpene Pl-4 is described. The key step is a regioselective chelation-controlled lithiation of the (Z)-configured bromide in the corresponding vinyl dibromide precursor. The method outlined within this Article is suitable for the facile access of sterically hindered internal vinyl halides for further coupling reactions.
