- Enantioselective Total Synthesis of (+)-Nordasycarpidone, (+)-Dasycarpidone, and (+)-Uleine
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The structure of uleine type alkaloids is characterized by the presence of a bridged tetracyclic hexahydro-1H-1,5-methanoazocino[4,3-b]indole ring system 1. Various strategies have been developed to access this polycyclic structural motif. We report herein a one-step conversion of appropriately functionalized 1,3,4-trisubstituted cyclopent-1-ene to 1 by way of an integrated oxidation/reduction/cyclization (iORC) process. This domino sequence, initiated by oxidative cleavage of cyclopentene ring, generated subsequently a cyclohexenone, an indole and a 1,3-bridged piperidine ring through formation of one C?C and two C?N bonds. Compound 1 is subsequently converted to nordasycarpidone, dasycarpidone and uleine. The chirality of the molecule was introduced by enzymatic desymmetrization of commercially available meso cis-3,5-diacetoxy-1-cyclopentene.
- Delayre, Bastien,Fung, Cédric,Wang, Qian,Zhu, Jieping
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- TiCl3-Mediated Synthesis of 2,3,3-Trisubstituted Indolenines: Total Synthesis of (+)-1,2-Dehydroaspidospermidine, (+)-Condyfoline, and (?)-Tubifoline
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2,3,3-Trisubstituted indolenine constitutes an integral part of many biologically important monoterpene indole alkaloids. We report herein an unprecedented access to this skeleton by a TiCl3-mediated reductive cyclization of tetrasubstituted alkenes bearing a 2-nitrophenyl substituent. The proof of concept is demonstrated firstly by accomplishing a concise total synthesis of (+)-1,2-dehydroaspidospermidine featuring a late-stage application of this key transformation. A sequence of reduction of nitroarene to nitrosoarene followed by 6π-electron-5-atom electrocyclization and a 1,2-alkyl shift of the resulting nitrone intermediate was proposed to account for the reaction outcome. A subsequent total synthesis of (+)-condyfoline not only illustrates the generality of the reaction, but also provides a mechanistic insight into the nature of the 1,2-alkyl shift. The exclusive formation of (+)-condyfoline indicates that the 1,2-alkyl migration follows a concerted Wagner–Meerwein pathway, rather than a stepwise retro-Mannich/Mannich reaction sequence. Conditions for almost quantitative conversion of (+)-condyfoline to (?)-tubifoline by way of a retro-Mannich/1,3-prototropy/transannular cyclization cascade are also documented.
- Delayre, Bastien,Piemontesi, Cyril,Wang, Qian,Zhu, Jieping
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supporting information
p. 13990 - 13997
(2020/06/10)
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- SYNTHESIS OF DELTA 12-PGJ3 AND RELATED COMPOUNDS
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In one aspect, the present invention provides novel derivatives of Δ12-PGJ3 and modular synthetic pathways to obtaining Δ12-PGJ3 and derivatives thereof. In some aspects, the present derivatives of Δ12-PGJ3 are useful as chemotherapeutic agents. The present disclosure also describes compositions of these derivatives as well as methods of use of the derivatives thereof.
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Page/Page column 94
(2015/04/15)
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- Convenient synthesis of the key intermediate for dihydrocorynantheol and protoemetinol from the monoacetate of 4-cyclopentene-1,3-diol
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We invented an efficient method to obtain the key δ-lactone possessing the (CH2)2OTBDPS and Et groups at C3 and C4, respectively, starting with the acetate of 4-cyclopentene-1,3-diol, which was subjected to Pd-catalyzed allylation with malonate anion to attach the (CH 2)2OTBDPS group. The Et group was then installed by 1,4-addition to the derived enone. Finally, the resulting enol TMS ether was oxidized to afford the lactone. Furthermore, the lactone was converted to dihydrocorynantheol and protoemetinol, both of which are typical examples of indoloquinolizidine and benzo[α]quinolizine alkaloids. The Japan Institute of Heterocyclic Chemistry.
- Kobayashi, Yuichi,Yagi, Kaori,Kaneko, Yuki
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scheme or table
p. 1541 - 1548
(2011/05/05)
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- Strategy for synthesis of the isoleucine conjugate of epi-jasmonic acid
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The TES ether of 2-((1R,2S,3R)-3-hydroxy-2-((Z)-pent-2-enyl)cyclopentyl)acetic acid (5, equal to the reduction product of epi-jasmonic acid) derived from (1R,4S)-4-hydroxycyclopent-2-enyl acetate (19) in 13 steps was activated by using isobutyl chloroformate and was subjected to condensation with isoleucine at room temperature for 48 h. The product was desilylated and oxidized to the isoleucine conjugate of epi-jasmonic acid in 68% yield over three steps. Similarly, allo-isoleucine conjugate of epi-jasmonic acid and three isoleucine conjugates of ent-epi-jasmonic acid, jasmonic acid, and ent-jasmonic acid were synthesized.
- Ogawa, Narihito,Kobayashi, Yuichi
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scheme or table
p. 7124 - 7127
(2009/04/10)
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- Regulation of type 5 adenylyl cyclase for treatment of neurodegenerative and cardiac diseases
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The invention concerns pharmaceutical compositions that contain a compound or compounds that can effectively regulate the activity of Type 5 Adenylyl Cyclase and methods for treatment of neurological diseases and disorders, as well as motor function loss
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Page/Page column 32
(2010/11/24)
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- Highly efficient total synthesis of Δ12-PGJ2, 15-deoxy-Δ12,14-PGJ2, and their analogues
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Palladium-catalyzed reaction of TBS ether of 4-cyclopentene-1,3-diol monoacetate (>95% ee) with an anion derived from methyl malonate and a base such as t-BuOK and LDA proceeded highly efficiently and reproducibly. The product obtained in >90% isolated yield was transformed in five steps into the key cyclopentenone possessing the α-chain at the γ position. Aldol reaction of this enone with the ω-chain aldehyde afforded the aldol adduct, and exposure of the derived mesylate to Al2O3 furnished the cross-conjugated dienone of the full structure. Finally, functional group manipulation furnished Δ12-PGJ2 efficiently. Similarly, 15-deoxy-Δ12,14-PGJ2, 5,6-acetylene analogues, and a 5,6-dihydro analogue were synthesized.
- Acharya, Hukum P.,Kobayashi, Yuichi
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p. 3329 - 3343
(2007/10/03)
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- Stereocontrolled synthesis of quinine and quinidine
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Disubstituted cyclopentene was prepared from cyclopentene monoacetate and transferred into disubstituted piperidine via oxidative cleavage of the olefin moiety followed by piperidine ring formation. The piperidine was then condensed at the side chain with a quinoline part to afford the olefin precursor of quinine. Finally, the olefin was converted into quinine through the corresponding epoxide. Quinidine was synthesized in a similar way.
- Igarashi, Junji,Katsukawa, Masahiro,Wang, Yong-Gang,Acharya, Hukum P.,Kobayashi, Yuichi
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p. 3783 - 3786
(2007/10/03)
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- Metal coordination-based inhibitors of adenylyl cyclase: Novel potent P-site antagonists
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The adenylyl cyclases (ACs) are a family of intracellular enzymes associated with signal transduction by virtue of their ability to convert ATP to cAMP. The catalytic mechanism of this transformation proceeds through initial binding of ATP to the so-calle
- Levy, Daniel E.,Bao, Ming,Cherbavaz James, Diana B.,Tomlinson,Sedlock, David M.,Homcy, Charles J.,Scarborough, Robert M.
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p. 2177 - 2186
(2007/10/03)
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- Synthesis of α- and β-D,L-ribo-carbahex-2-ulofuranose
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Both α- and β-D,L-ribo-carbahex-2-ulofuranose have been synthesized in racemic form starting from norbornen-2-one. In the course of the synthesis the reaction of sulfur ylides with α-alkoxyketones took an unexpected stereochemical pathway.
- Marschner,Penn,Griengl
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p. 5067 - 5078
(2007/10/02)
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- A total synthesis of a protected form of the secoxyloganin aglucone
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A synthesis is described that leads from cyclopentadiene through 5-norbornen-2-one to the monosubstituted cyclopentanone 5; a vinyl substituent is attached by the reaction of a cuprate, and the enolate intermediate is trapped as the silyl enol ether 4, which is converted to 19, a product with the 10-carbon framework and stereochemistry of the secoxyloganin aglucone, and with all functional groups differentially protected and in the correct oxidation state.Explorations of the cuprate reaction required to convert the cyclopentenone 5 to the siloxycyclopentene 4 and of the reactions required for the oxidative cleavage of 4 reveal problems with these reactions when they are applied to compounds that are cyclopentane derivatives.The resolution of these problems leads to reaction sequences that proceed with high yields and excellent diastereoselectivity.Keywords: synthesis, secoxyloganin, vinyl cuprate, oxidative cleavage
- Cheng, Peter T. W.,McLean, Stewart
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p. 261 - 267
(2007/10/02)
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- PREPARATION OF METHYL 10-OXO-15S-HYDROXYPROSTA-5E,13Z-DIENOATE
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The synthesis of methyl 10-oxo-15S-hydroxyprosta-5E,13Z-dienoate
- Arndt, Henry C.,Rajani, Cynthia
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p. 2365 - 2368
(2007/10/02)
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