- Stereoselective total synthesis of (-)-(5S,8R,13S,16R)-pyrenophorol
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The total synthesis of 16-membered C2-symmetric dilactone (-)-(5S,8R,13S,16R)-pyrenophorol was accomplished starting from enantiomerically pure propylene oxide prepared by hydrolytic kinetic resolution of (±)-propylene oxide with key steps of cross-metathesis and intermolecular Mitsunobu cyclization for the construction of macrolactone.
- Edukondalu, Perugu,Sreenivasulu, Reddymasu,Raju, Rudraraju Ramesh,Chiranjeevi, Barreddi,Kumar, Vuppula Naresh
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- Macrodiolide Diversification Reveals Broad Immunosuppressive Activity That Impairs the cGAS-STING Pathway
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The development of new immunomodulatory agents can impact various areas of medicine. In particular, compounds with the ability to modulate innate immunological pathways hold significant unexplored potential. Herein, we report a modular synthetic approach to the macrodiolide natural product (?)-vermiculine, an agent previously shown to possess diverse biological effects, including cytotoxic and immunosuppressive activity. The synthesis allows for a high degree of flexibility in modifying the macrocyclic framework, including the formation of all possible stereoisomers. In total, 18 analogues were prepared. Two analogues with minor structural modifications showed clearly enhanced cancer cell line selectivity and reduced toxicity. Moreover, these compounds possessed broad inhibitory activity against innate immunological pathways in human PBMCs, including the DNA-sensing cGAS-STING pathway. Initial mechanistic characterization suggests a surprising impairment of the STING-TBK1 interaction.
- Biltoft, Mette,Jakobsen, Martin R.,Jennet, Kira M.,Kristensen, Tobias F.,Liu, Han,Ottosen, Rasmus N.,Poulsen, Thomas B.,Svenningsen, Esben B.
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p. 18734 - 18741
(2021/07/19)
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- An alternative stereoselective total synthesis of (-)-pyrenophorol
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The total synthesis of 16-membered C2–Symmetric dilactone (-)-Pyrenophorol was accomplished starting from commercially available (S)-epoxide prepared by hydrolytic kinetic resolution of (±)–epoxide with key steps of Grignard reaction, Swern oxidation, Wittig reaction and cyclization was achieved by intermolecular Mitsunobu cyclization. The synthesis of (-)-Pyrenophorol accomplished from cheaply available starting material, easily work-up procedures and reduction of cost in industrial process were major advantages of this route.
- Alluraiah, Gurrala,Sreenivasulu, Reddymasu,Chandrasekhar, Choragudi,Raju, Rudraraju Ramesh
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p. 2738 - 2743
(2018/09/25)
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- Stereoselective total synthesis of (?)-pyrenophorol
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Abstract: A simple and efficient stereoselective synthesis of macrodilactone of (?)-pyrenophorol (1) has been accomplished in 12 steps in 8.3% overall yield, from inexpensive and commercially available (S)-ethyl lactate. This convergent synthesis utilizes an oxidation–reduction protocol and cyclodimerisation under the Mitsunobu reaction conditions as key steps.
- Ashok, Dongamanti,Pervaram, Sridhar,Chittireddy, Venkata Ramana Reddy,Reddymasu, Sreenivasulu,Vuppula, Naresh Kumar
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p. 971 - 977
(2018/03/28)
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- Asymmetric hydroformylation-initiated tandem sequences for syntheses of (+)-patulolide C, (-)-pyrenophorol, (+)-decarestrictine L, and (+)-prelog djerassi lactone
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Four different Rh-catalyzed asymmetric hydroformylation (AHF) tandem reactions have been developed in the context of the total syntheses of (+)-patulolide C, (-)-pyrenophorol, (+)-decarestrictine L, and (+)-Prelog-Djerassi lactone. A total synthesis of (+)-patulolide C has been accomplished in three steps utilizing a Rh(I)-catalyzed Z-selective anti-Markovnikov hydroacetoxylation of a known alkyne to give a Z-enol acetate with excellent selectivity. An AHF/intramolecular Wittig olefination cascade was utilized to set the C4-hydroxyl stereochemistry, E-olefin geometry, and form the macrolactone. In addition, both (-)-pyrenophorol and (+)-decarestrictine L have been synthesized from the enantiomeric (4R)- and (4S)-4-(tert-butyldimethylsiloxy)-1-pentyne in five and four steps, respectively. These syntheses feature Ru(II)-catalyzed Z-selective anti-Markovnikov hydroacetoxylation of terminal alkynes followed by AHF/Wittig olefination sequences to rapidly establish functionality and stereogenicity. A synthesis of (+)-Prelog-Djerassi lactone was accomplished in three isolations from the known 1-vinyl-4-methyl-2,6,7-trioxabicyclo[2.2.2]-octane ortho ester. An AHF/crotylation tandem sequence has been developed to set the C2-C4 stereochemistry. An asymmetric hydrogenation was employed to set the C6 stereochemistry, resulting in an especially efficient enantioselective synthesis from achiral starting material. In summary, these syntheses have greatly improved efficiency in terms of atom-economy, catalytic stereoselective transformations, inexpensive reagents, step-counts, and overall yield when compared with previous synthetic attempts.
- Risi, Roberto M.,Maza, Andrew M.,Burke, Steven D.
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p. 204 - 216
(2016/09/09)
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- A chemoenzymatic synthesis of hept-6-ene-2,5-diol stereomers: Application to asymmetric synthesis of decarestrictine L, pyrenophorol, and stagonolide e
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The stereomers of hept-6-ene-2,5-diol derivatives were conceived as useful chiral intermediates and were synthesized starting from sulcatol using two lipase-catalyzed acylation reactions as the key steps. The versatility of the intermediates was demonstrated by converting them to the titled tetrahydropyran, macrolide, and macrodiolide compounds using standard synthetic protocols.
- Chatterjee, Sucheta,Ghadigaonkar, Sneha,Sur, Payel,Sharma, Anubha,Chattopadhyay, Subrata
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p. 8067 - 8076
(2015/03/18)
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- Total synthesis of (-)-pyrenophorol
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An efficient synthetic route has been developed for the synthesis of (-)-pyrenophorol employing Sharpless asymmetric epoxidation, olefin cross-metathesis, and intermolecular Mitsunobu cyclization. Georg Thieme Verlag Stuttgart · New York.
- Yadav, Jhillu S.,Reddy, Ganapuram Madhusudhan,Rao, Tenneti Srinivasa,Reddy, Basi V. Subba,Al Khazim Al Ghamdi, Ahmad
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p. 783 - 787
(2012/04/10)
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- Stereoselective total synthesis of (-)-pyrenophorol
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An efficient stereoselective total synthesis of (-)-pyrenophorol 1 is described. The key steps involved in this synthesis are hydrolytic kinetic resolution (HKR), MacMillan α-hydroxylation, Horner-Wadsworth-Emmons (HWE) reaction, and Mitsunobu cyclization
- Yadav,Subba Reddy,Subba Reddy
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scheme or table
p. 5984 - 5986
(2010/02/28)
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- A New Approach to the Synthesis of γ-Hydroxy-α,β-unsaturated Macrolides and (-)-Pyrenophorin by Intramolecular C=C Bond Formation with Oxidative Functionalization from ω-alkanal
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The title compounds were prepared via the intramolecular condensation reaction of 12-tridecanal(or dodecanal) or via the combination of inter- and intramolecular condensation of 5-hexanal in the presence of piperidine.
- Nokami, Junzo,Taniguchi, Takuya,Gomyo, Shintaro,Kakihara, Toshio
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p. 1103 - 1106
(2007/10/02)
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- Preparation of macrodiolides via a common chiral building block. Total synthesis of (-)-pyrenophorin and (-)-pyrenophorol
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Macrodiolides (-)-pyrenophorin and (-)-pyrenophorol have been synthesized utilizing a C2 symmetric (R,R)-diepoxide as a common enantiopure chiral building block.
- Machinaga, Nobuo,Kibayashi, Chihiro
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p. 841 - 844
(2007/10/02)
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- Total synthesis of the macrodiolide pyrenophorol
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By means of a total synthesis, the absolute configuration of the naturally occurring macrodiolide pyrenophorol has been established. An essential step is the photo-induced rearrangement of an α,β-epoxy diazomethyl ketone to produce a 4-hydroxy-2-alkenoate. The two lactone units have been introduced in two successive steps.
- Dommerholt,Thijs,Zwanenburg
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p. 1499 - 1502
(2007/10/02)
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- A SHORT-STEP SYNTHESIS OF (+/-)-PYRENOPHORIN UTILIZING 3-ALKENOATE AS A MASKED SYNTHON OF 4-OXO-2-ALKENOATE
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The use of 3-alkenoate as a masked synthon of 4-oxo-2-alkenoate was established by a three step conversion of 3-noneonate into 4-oxo-2-nonenoate through epoxidation, isomerization to an allyl silyl ether, and oxidation in a high overall yield.This method was applied to the short step synthesis of pyrenophorin from 7-oxo-3-octenoic acid.
- Fujisawa, Tamotsu,Takeuchi, Masashi,Sato, Toshio
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p. 1795 - 1798
(2007/10/02)
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- A Short Synthesis of (R,R)-(-)-Pyrenophorin from (S)-Propylene Oxide and a 3-Pentenoic Acid d5-Reagent
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Analysis of the known syntheses of pyrenophorin (1) (Scheme 1) reveals that they all rest upon the use of reagents with d1-, d3-, or a2-reactivity umpolung for the establishment of at least one of the 1,4-distances of functional groups.A different approach, outlined in Scheme 2, has now been realized: the non-conjugated and the conjugated 7-hydroxyoctenoic acids 10 and 11, obtained from dienone dianion derivatives of type 3 and d,l- or (S)-methyloxirane, are converted to the macrodiolides 12 and 13, respectively.These are directly oxidized with introduction of an oxygen function at position 4, see 13 -> 1 and 12 -> 16 -> 17 -> 1.The overall transformation of the γ,δ-unsaturated ketone 18 to pyrenophorin (1) in 27 percent yield takes six steps, partly without purification of intermediates.
- Mali, Raghao S.,Pohmakotr, Manat,Weidmann, Beat,Seebach, Dieter
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p. 2272 - 2284
(2007/10/02)
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