- Total Synthesis of Disciformycin A and B: Unusually Exigent Targets of Biological Significance
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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
- Kwon, Yonghoon,Schulthoff, Saskia,Dao, Quang Minh,Wirtz, Conny,Fürstner, Alois
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- PROCESS FOR THE PREPARATION OF MACROCYCLIC KETONE ANALOGS OF HALICHONDRIN B
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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.
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Page/Page column 41-42
(2019/11/19)
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- Polyoxygenated Tertiary Alcohols: A Kiyooka Approach
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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
- Lücke, Daniel,Kalesse, Markus
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supporting information
p. 10080 - 10083
(2019/07/18)
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- Preparation of Alkyl Ethers with Diallyltriazinedione-Type Alkylating Agents (ATTACKs-R) Under Acid Catalysis
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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.
- Fujita, Hikaru,Yamashita, Rina,Fujii, Takanori,Yamada, Kohei,Kitamura, Masanori,Kunishima, Munetaka
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p. 4436 - 4446
(2019/07/03)
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- Nhatrangin A: Total Syntheses of the Proposed Structure and Six of Its Diastereoisomers
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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.
- Dias, Luiz C.,Polo, Ellen C.
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p. 4072 - 4112
(2017/04/28)
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- Towards the total synthesis of the anti-trypanosomal macrolide, Actinoallolides: Construction of a key linear intermediate
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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.
- Oshita, Jun,Noguchi, Yoshihiko,Watanabe, Akito,Sennari, Goh,Sato, Shogo,Hirose, Tomoyasu,Oikawa, Daiki,Inahashi, Yuki,Iwatsuki, Masato,Ishiyama, Aki,Omura, Satoshi,Sunazuka, Toshiaki
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supporting information
p. 357 - 360
(2016/01/12)
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- Directed hydrogenations and an Ireland-Claisen rearrangement linked to Evans-Tishchenko chemistry: The highly efficient total synthesis of the marine cyclodepsipeptide doliculide
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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.
- Chen, Tao,Altmann, Karl-Heinz
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supporting information
p. 8403 - 8407
(2015/06/02)
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- Concise diastereoselective synthesis of calcaripeptide C via asymmetric transfer hydrogenation/Pd-induced chiral allenylzinc as a key reaction
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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.
- Kumaraswamy, Gullapalli,Narayanarao, Vykunthapu,Raju, Ragam
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supporting information
p. 8487 - 8494
(2015/08/06)
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- Chemoselective formation of unsymmetrically substituted ethers from catalytic reductive coupling of aldehydes and ketones with alcohols in aqueous solution
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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.
- Kalutharage, Nishantha,Yi, Chae S.
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supporting information
p. 1778 - 1781
(2015/04/14)
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- Synthetic studies towards an advanced precursor of the jatrophane diterpene Pl-4
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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.
- Fürst, Rita,Lentsch, Christoph,Rinner, Uwe
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supporting information
p. 357 - 367
(2014/02/14)
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- Prediction and determination of the stereochemistry of the 1,3,5-trimethyl-substituted alkyl chain in verucopeptin, a microbial metabolite
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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
- Yoshimura, Aya,Kishimoto, Shinji,Nishimura, Shinichi,Otsuka, Saori,Sakai, Yuki,Hattori, Akira,Kakeya, Hideaki
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p. 6858 - 6867
(2014/08/18)
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- Synthesis of spongistatin 2 employing a new route to the EF fragment
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An improved route to the EF fragment of the spongistatins has been developed and employed in a synthesis of spongistatin 2. The C48-C51 diene side chain, which lacks the chlorine substituent present in spongistatin 1, presented some compatibility issues d
- Kraus, Helmut,Francais, Antoine,O'Brien, Matthew,Frost, James,Dieguez-Vazquez, Alejandro,Polara, Alessandra,Baricordi, Nikla,Horan, Richard,Hsu, Day-Shin,Tsunoda, Takashi,Ley, Steven V.
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p. 1989 - 1994
(2013/06/05)
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- A practical method for p -methoxybenzylation of hydroxy groups using 2,4,6-tris(p -methoxybenzyloxy)-1,3,5-triazine (TriBOT-PM)
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A new acid-catalyzed p-methoxybenzylating reagent, 2,4,6-tris(p- methoxybenzyloxy)-1,3,5-triazine (TriBOT-PM), has been developed. The reaction of acid- and alkali-labile alcohols with TriBOT-PM in the presence of a catalytic amount of various acids (TfOH, BF3·OEt2, CSA, etc.) afforded the corresponding p-methoxybenzyl ethers in good yields. Since TriBOT-PM is an air-stable crystalline solid and can be prepared from inexpensive materials, i.e. cyanuric chloride and anisyl alcohol, this route is of practical use. Georg Thieme Verlag Stuttgart, New York.
- Yamada, Kohei,Fujita, Hikaru,Kitamura, Masanori,Kunishima, Munetaka
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p. 2989 - 2997
(2013/11/06)
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- Stereoselectivity of model C22-23 aldol coupling for spirangiens A & B
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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.
- Gregg, Claire,Perkins, Michael V.
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supporting information
p. 387 - 394
(2013/01/15)
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- Synthesis of an advanced intermediate of the jatrophane diterpene Pl-4: A dibromide coupling approach
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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.
- Fuerst, Rita,Rinner, Uwe
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p. 8748 - 8758
(2013/09/24)
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- Formal synthesis of dictyostatin and synthesis of two dictyostatin analogues
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A formal convergent synthesis of dictyostatin from (R)-Roche ester is described. Synthetic highlights include a Ni-catalyzed Nozaki-Hiyama-Kishi coupling between an aldehyde and a Z vinyl iodide to assemble the two main fragments, a diastereoselective Myers alkylation, a stereoselective Evans aldolization, two asymmetric Duthaler crotyltitanations, and a stereoselective Pd-catalyzed Marshall allenylindium addition to install the stereogenic centers of dictyostatin. The synthesis of (9R)-epi-dictyostatin and a new ring-contracted dictyostatin isomer were also achieved. Copyright
- Gallon, Julien,Esteban, Jorge,Bouzbouz, Samir,Campbell, Matthew,Reymond, Sébastien,Cossy, Janine
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supporting information
p. 11788 - 11797
(2012/11/07)
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- Reagent for synthesis of para-methoxbenzyl (PMB) ethers and associated methods
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A newly synthesized compound designated lepidine ether 2-(4-Methoxybenzyloxy)-4-methylquinoline reacts with methyl triflate in the presence of alcohols to generate a neutral organic salt that transfers the para-methoxybenzyl (PMB) protecting group onto al
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Page/Page column 3; 4
(2011/06/25)
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- Synthesis of the C1-C12 acid fragment of amphidinolide T marine macrolides via SmI2-mediated enantioselective reductive coupling of aldehydes with a chiral crotonate
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A new strategy for enantioselective assembly of the trisubstituted tetrahydrofuran ring has been established for synthesis of the C1-C12 acid fragment of amphidinolide T series marine macrolides. The key steps involve the SmI2-mediated highly e
- Luo, Jialu,Li, Huoming,Wu, Jinlong,Xing, Xinglong,Dai, Wei-Min
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supporting information; experimental part
p. 6828 - 6833
(2009/12/06)
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- A mild method for the protection of alcohols using a para-methoxybenzylthio tetrazole (PMB-ST) under dual acid-base activation
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With a view to expand the repertoire of chemoselective methods applicable to sensitive and multifunctional substrates, the p-methoxybenzylation of alcohols under essentially neutral conditions is reported. This was achieved by the silver triflate (AgOTf) activation of 5-(p-methoxybenzylthio)-1-phenyl-1H-tetrazole (PMB-ST) in the presence of 2,6-di-tert-butyl-4-methylpyridine (DTBMP).
- Kotturi, Santosh R.,Tan, Jason S.,Lear, Martin J.
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supporting information; experimental part
p. 5267 - 5269
(2009/12/24)
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- A concise total synthesis of saliniketal B
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(Chemical Equation Presented) We report a concise, enantioselective, and highly efficient synthesis of the marine actinomycete-derived natural product saliniketal B. Our approach was motivated with an eye toward future structure-function studies of this inhibitor of phorbol ester-mediated ornithine decarboxylase induction via an unknown mechanism. Our strategy highlights the utility of Pt (II)-mediated cycloisomerization of alkynediols developed in our laboratory to construct the dioxabicyclo[3.2.1]octane ring system, a highly selective aldol fragment coupling whose stereochemical outcome is influenced by a γ-stereogenic methyl group, and an interesting one-pot desilylation/dihydropyranone fragmentation/amidation sequence. As such, saliniketal B was obtained in 11 steps and 23% overall yield from commercially available starting material via a convergent coupling of two equally complex fragments assembled in seven and eight steps (39 and 45%), respectively.
- Liu, Jun,De Brabander, Jef K.
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scheme or table
p. 12562 - 12563
(2010/01/30)
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- Synthesis of the C10-C32 core structure of spirangien A
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(Chemical Equation Presented) The synthesis of the C10-C32 core structure of spirangien A is reported. The pivotal aldol coupling between both key intermediates provides a synthetic challenge in the synthesis of this complex natural product.
- Lorenz, Michael,Kalesse, Markus
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supporting information; experimental part
p. 4371 - 4374
(2009/06/06)
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- Confirmation of the stereostructure of (+)-cytostatin by fluorous mixture synthesis of four candidate stereoisomers
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Mix and match: Four closely related candidate isomers for cytostatin have been synthesized by using the technique of fluorous mixture synthesis. Comparison of NMR, thin-layer chromatography, and optical rotation data enabled the three isomers that were not cytostatin to be identified. Thus, by a process of elimination (disproof), the isomer corresponding to cytostatin was determined, and the 4S,5S,6S,9S,10S,11S configuration confirmed. (Chemical Equation Presented).
- Jung, Won-Hyuk,Guyenne, Sabrina,Riesco-Fagundo, Concepcion,Mancuso, John,Nakamura, Shuichi,Curran, Dennis P.
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p. 1130 - 1133
(2008/09/21)
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- Synthesis of para-methoxybenzyl (PMB) ethers under neutral conditions
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2-(4-Methoxybenzyloxy)-4-methylquinoline reacts with methyl triflate in the presence of alcohols to generate a neutral organic salt that transfers the para-methoxybenzyl (PMB) protecting group onto alcohols in high yield and under mild conditions. The Royal Society of Chemistry.
- Nwoye, Ernest O.,Dudley, Gregory B.
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p. 1436 - 1437
(2008/02/02)
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- First stereoselective synthesis of the C(1)-C(13) fragment of dolabelides using ruthenium-SYNPHOS-catalyzed asymmetric hydrogenation reactions
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The first stereocontrolled synthesis of the C(1)-C(13) fragment of cytotoxic macrolides dolabelides is reported. The C(3), C(7), C(9) and C(11) hydroxyl-bearing stereocenters were installed using ruthenium-mediated asymmetric hydrogenation reactions of the adequate β-keto esters and β-hydroxy ketone. Georg Thieme Verlag Stuttgart.
- Le Roux, Rémi,Desroy, Nicolas,Phansavath, Phannarath,Genêt, Jean-Pierre
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p. 429 - 432
(2007/10/03)
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- Natural product-guided synthesis of a spiroacetal collection reveals modulators of tubulin cytoskeleton integrity
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The spiro[5.5]ketal moiety forms the underlying structural skeleton of numerous biologically active natural products. Since simplified but characteristic spiroketals derived from the parent natural products retain biological activity, the spiro[5.5]ketal
- Barun, Okram,Kumar, Kamal,Sommer, Stefan,Langerak, Anette,Mayer, Thomas U.,Mueller, Oliver,Waldmann, Herbert
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p. 4773 - 4788
(2007/10/03)
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- A short approach to the bicyclo[4.3.0]nonane fragment of stawamycin
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The bicyclo[4.3.0]nonane (C11-C21) fragment of stawamycin has been prepared by a sequence involving 11 steps (10% overall yield) from methyl (R)-(-)-3-hydroxy-2-methylpropionate. Key steps are a Pd-catalysed Stille coupling reaction
- Dias, Luiz C.,Melgar, Gliseida Z.,Jardim, Luciana S. A.
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p. 4427 - 4431
(2007/10/03)
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- Total Synthesis of the Boron-Containing Ion Carrier Antibiotic Macrodiolide Tartrolon B
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The first total synthesis of the boron-containing macrodiolide antibiotic tartrolon B is reported in full detail. Two convergent approaches to the target compound are described, the first of which eventually failed, due to sensitive functionality. In the
- Mulzer, Johann,Berger, Markus
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p. 891 - 898
(2007/10/03)
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- Enantioselective preparation of asymmetrically protected 2-propanoyl-1,3-propanediol derivatives: Toward the total synthesis of Kazusamycin A
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The preparation of enantiomerically pure 2-propanoyl-1,3-propanediol derivatives, key intermediates in our studies on total synthesis of the potent antitumor compound Kazusamycin A are described. After various enzymatic protocols for desymmetrization of t
- Arai, Noriyoshi,Chikaraishi, Noriko,Ikawa, Mitsuhiro,Omura, Satoshi,Kuwajima, Isao
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p. 733 - 741
(2007/10/03)
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- The synthesis of deoxyfusapyrone. 2. Preparation of the bis-trisubstituted olefin fragment and its attachment to the pyrone moiety
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A convergent and modular synthesis has been devised to construct the eight diastereoisomers of deoxyfusapyrone (1). In this paper the synthesis of the complex polyene chain is reported as is its connection to the pyrone moiety that is in the middle of the
- Organ, Michael G.,Wang, Junquan
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p. 5568 - 5574
(2007/10/03)
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- Convergent enantioselective synthesis of vinigrol, an architecturally novel diterpenoid with potent platelet aggregation inhibitory and antihypertensive properties. 1. Application of anionic sigmatropy to construction of the octalin substructure
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The coupling of building blocks 15 and 36e in the presence of MgBr2·OEt2 at 0 °C proceeds with an exo stereoselectivity (3.2:1) considerably more advantageous for the acquisition of carbinol 37e than in the absence of the additive (exo/endo = 1:5.7). The pivotal transformation that sets all of the relevant stereocenters of the cis-octalin 55 is the oxyanionic-accelerated [3,3]-sigmatropic rearrangement of 37e. A salient feature is the structurally enforced adoption of a boatlike transition state that serves to properly set four vicinal methine hydrogens in an all-cis arrangement. The ensuing conversion of 55 into iodo sulfone 62 has permitted X-ray crystallographic confirmation of all absolute stereochemical assignments since the isopropyl substituent was initially installed enantioselectively via the Evans oxazolidinone protocol. No intramolecular anionic cyclization of 62 to generate the tricyclic framework was seen. This absence of reactivity is attributed to conformational factors that inhibit attainment of the proper SN2 reaction trajectory.
- Paquette, Leo A.,Guevel, Ronan,Sakamoto, Shuichi,Kim In Ho,Crawford, Jason
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p. 6096 - 6107
(2007/10/03)
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- A Combinatorial Synthesis of a Macrosphelide Library Utilizing a Palladium-Catalyzed Carbonylation on a Polymer Support
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Supported total synthesis: The combinatorial synthesis of a 122-membered macrosphelide library including macrosphelides A, C, E, and F (see picture) has been achieved based on a unique strategy for a three-component coupling utilizing a palladium-catalyzed chemoselective carbonylation and an unprecedented macrolactonization on a polymer support.
- Takahashi, Takashi,Kusaka, Shin-Ichi,Doi, Takayuki,Sunazuka, Toshiaki,Omura, Satoshi
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p. 5230 - 5234
(2007/10/03)
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- Synthesis of a Diels-Alder precursor for the Elisabethin A skeleton
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A synthesis of a precursor 2 for the Elisabethin A skeleton is reported. Containing a masked quinone and a (E,Z)-diene sub-unit, it has the required elements for the envisaged intramolecular Diels-Alder reaction to form the tricyclic system of Elisabethin A. Starting from methylresorcinol, the sequence involves the preparation of an arylacetic acid, which was α-alkylated by a chiral building block. Subsequent HWE reaction and cis-selective Wittig olefination furnished the diene with the desired geometry.
- Heckrodt, Thilo J.,Mulzer, Johann
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p. 1857 - 1866
(2007/10/03)
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- Toward the combinatorial synthesis of polyketide libraries: Asymmetric aldol reactions with α-chiral aldehydes on solid support
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(Matrix presented) The viability of performing stereocontrolled aldol additions with α-chiral aldehydes attached by a silyl linker to a hydroxymethylpolystyrene resin is demonstrated for boron and titanium enolates. Subsequent ketone reduction and manipul
- Paterson, Ian,Temal-Laib, Taoues
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p. 2473 - 2476
(2007/10/03)
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- Activated dimethyl sulfoxide dehydration of amide and its application to one-pot preparation of benzyl-type perfluoroimidates
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Various types of primary amides were treated under an activated dimethyl sulfoxide (DMSO) species, (COCl)2-DMSO and Et3N, as a dehydrating agent to obtain nitriles in excellent yield. This dehydration system was extended to a one-pot preparation of perfluoroimidates via volatile perfluoronitriles from perfluoroamides. Fifteen benzyl-type perfluoroimidates can be prepared in 70-90% yield as more stable imidates than the trichloro analogue. MPM- and DMPM-perfluoroimidates can be used to protect alcohols in place of the trichloroacetimidate with excellent chemical properties and in comparable yields.
- Nakajima, Noriyuki,Saito, Miho,Ubukata, Makoto
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p. 3561 - 3577
(2007/10/03)
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- Studies directed toward the synthesis of the C15-C21 fragment of (-)-discodermolide
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A novel method developed by us recently for the synthesis of chiral 2-methyl-1,3-diols by radical-mediated diastereoselective opening of trisubstituted epoxy alcohols at the more substituted carbon serves as the key step in our studies directed toward the
- Chakraborty, Tushar K.,Laxman, Pasunoori
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p. 543 - 545
(2007/10/03)
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- Studies directed towards the total synthesis of the antibiotic macrodiolide tartrolon: EPC synthesis of the protected seco acid
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An efficient synthesis of the protected seco acid 2 of the antibiotic macrodiolide tartrolon 1 is described. Key steps are a substrate controlled aldol-reaction, a Johnson-Claisen rearrangement, and a Horner-Wadsworth-Emmons olefination with subsequent Co
- Mulzer, Johann,Berger, Markus
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p. 803 - 806
(2007/10/03)
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- Approaches to a synthesis of galbonolide B
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An approach to the C(7)-C(15) fragment of galbonolide B 2 has been completed in which the diene fragment 51 was assembled from (R)-3-tert-butyldimethylsilyloxypentan-2-one 29 by conversion into the unsaturated ester 30, acylation of the sulfone 47 using this ester, reductive desulfurisation, methylenation using a Wittig reaction and deprotection. Following model studies, the aldehyde 62, prepared by oxidation of the alcohol 51, was converted into a mixture of the epimeric alcohols 63 and these were converted into the di(methylene)tridecadienoic acid 65 using a phosphine catalysed Ireland-Claisen rearrangement. Sharpless epoxidations of the alcohol 67 using either L-(+)- or D-(-)-diethyl tartrate were highly stereoselective and gave the epoxides 68 and 69 which were clearly distinguishable. Model studies using the heptadiene monoepoxide 70 led to a synthesis of the monoprotected dihydroxy aldehyde 76 so establishing a protocol for the introduction into the vicinal diol of the galbonolides. Finally, aldol addition of tert-butyl acetate to the aldehyde 78 followed by selective protection, deprotection and cyclisation completed a synthesis of the macrolide 85.
- Smith, Peter M.,Thomas, Eric J.
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p. 3541 - 3556
(2007/10/03)
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- Preparation and reaction of 4-methoxybenzyl (MPM) and 3,4- dimethoxybenzyl (DMPM) perfluoroimidates
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We have succeeded in one-pot preparation of perfluoroimidates at -78 °C by employing the dehydration of perfluoroamide under the 'activated' dimethyl sulfoxide (DMSO) species followed by in situ nitrile trapping with alcohols. MPM and DMPM perfluoroimidates can be used to protect alcohols in place of the trichloroacetimidate with excellent chemical properties and in comparable yields.
- Nakajima, Noriyuki,Saito, Miho,Ubukata, Makoto
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p. 5565 - 5568
(2007/10/03)
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- A mild method for generation of p-methoxybenzyl cation through NIS- mediated activation of p-methoxybenzyl 4-pentenyl ether
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A mild and facile method for generation of p-methoxybenzyl cation through NIS-mediated activation of p-methoxybenzyl 4-pentenyl ether was achieved. Under the present activation conditions, various alcohols were convened to the corresponding p-methoxybenzyl ethers. A scope and limitation of the present p-methoxybenzylation reaction was also investigated.
- Okada,Kitagawa,Fujita,Taguchi
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p. 8135 - 8142
(2007/10/03)
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