scholarly journals Application of New Efficient Hoveyda–Grubbs Catalysts Comprising an N→Ru Coordinate Bond in a Six-Membered Ring for the Synthesis of Natural Product-Like Cyclopenta[b]furo[2,3-c]pyrroles

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5379
Author(s):  
Alexandra S. Antonova ◽  
Marina A. Vinokurova ◽  
Pavel A. Kumandin ◽  
Natalia L. Merkulova ◽  
Anna A. Sinelshchikova ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Natural Product ◽  
Alder Reaction ◽  
Membered Ring ◽  
Diels Alder ◽  
New Class ◽  
Diels Alder Reaction ◽  
Grubbs Catalysts ◽  
Coordinate Bond ◽  
Diastereomer Mixture

The ring rearrangement metathesis (RRM) of a trans-cis diastereomer mixture of methyl 3-allyl-3a,6-epoxyisoindole-7-carboxylates derived from cheap, accessible and renewable furan-based precursors in the presence of a new class of Hoveyda–Grubbs-type catalysts, comprising an N→Ru coordinate bond in a six-membered ring, results in the difficult-to-obtain natural product-like cyclopenta[b]furo[2,3-c]pyrroles. In this process, only one diastereomer with a trans-arrangement of the 3-allyl fragment relative to the 3a,6-epoxy bridge enters into the rearrangement, while the cis-isomers polymerize almost completely under the same conditions. The tested catalysts are active in the temperature range from 60 to 120 °C at a concentration of 0.5 mol % and provide better yields of the target tricycles compared to the most popular commercially available second-generation Hoveyda–Grubbs catalyst. The diastereoselectivity of the intramolecular Diels–Alder reaction furan (IMDAF) reaction between starting 1-(furan-2-yl)but-3-en-1-amines and maleic anhydride, leading to 3a,6-epoxyisoindole-7-carboxylates, was studied as well.

scholarly journals Studies towards the Synthesis of the Antibiotic Tetrodecamycin

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1117-1121
Author(s):  
Victor Lee ◽  
Jing He ◽  
Jack Baldwin
Keyword(s):  
Natural Product ◽  
Wittig Reaction ◽  
Alder Reaction ◽  
Membered Ring ◽  
Diels Alder ◽  
Acid Moiety ◽  
Tetronic Acid ◽  
Diels Alder Reaction

A study towards the natural product tetrodecamycin is reported. A modified Schlosser–Wittig reaction was utilized to prepare the precursor for the subsequent intramolecular Diels–Alder reaction, which delivered the trans-decalin ring of the natural product. The tetronic­ acid moiety of the molecule was prepared by a Dieckmann cyclization­. The cyclization of the tetronic acid to the trans-decalin double­ bond to form a seven-membered ring was examined.

scholarly journals Studies on the transannular Diels–Alder reaction of 15-membered macrocyclic trienes containing a trans-trans diene. Part I: Synthesis and isomerization of various model cyclopentadecatrienes

1995 ◽  
Vol 73 (10) ◽  
pp. 1675-1694 ◽  
Author(s):  
Dennis G. Hall ◽  
Renate Müller ◽  
Pierre Deslongchamps
Keyword(s):  
Aqueous Media ◽  
Alder Reaction ◽  
Membered Ring ◽  
Diels Alder ◽  
Coupling Reactions ◽  
Diels Alder Reaction ◽  
Trans Diene

The transannular Diels–Alder reaction of 15-membered macrocyclic trienes with a trans-trans-cis (TTC) olefin geometry can lead to A.B.C.[6.6.7] tricyclic products of trans-syn-trans (TST) and cis-syn-cis (CSC) stereochemistry whereas the TTT isomers can produce the trans-anti-cis (TAC) and cis-anti-trans (CAT) tricycles. In order to study the influence of the position (pro-6.6 or pro-6.7) and the nature (alkyl, alkoxymethyl, or formyl) of the dienophile substituent, a set of 10 model cyclopentadecatrienes was prepared. The synthesis of appropriately functionalized trisubstituted dienophile and diene synthons, as well as their coupling reactions affording acyclic precursors, is described in this paper (first in a series of two). A mild and efficient macrocyclization protocol yielded the required methyl- or alkoxymethyl-substituted cyclic substrates. Further transformations led to the formyl-substituted ones. In particular, the TTT macrocycles containing an enal as a dienophile could be completely isomerized to the corresponding TTC thermodynamic isomers in acidic aqueous media. Keywords: transannular, Diels–Alder, 15-membered ring, A.B.C.[6.6.7] tricycles, diterpene.

Hetero-Diels-Alder Reactions of Enaminothione with Electrophilic Olefins. Synthesis of 2-Furyl Substituted 2H-Thiopyrans

2002 ◽  
Vol 57 (6) ◽  
pp. 637-644 ◽  
Author(s):  
Krystyna Bogdanowicz-Szwed ◽  
Artur Budzowski
Keyword(s):  
Acetic Acid ◽  
Maleic Anhydride ◽  
Acetic Anhydride ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diethyl Maleate ◽  
Diels Alder Reaction

AbstractThe hetero-Diels-Alder reaction of 1-(2-furyl)-3-(dimethylamino)-2-propene-1-thione (diene) with maleic and fumaric acids, and β-nitrostyrenes yielded 3,4-dihydro-2H-thiopyran derivatives. Treatment of some of those cycloadducts with acetic acid caused elimination of dimethylamine yielding stable 2H-thiopyrans. Reaction of the diene with maleic anhydride furnished a cycloadduct which underwent spontaneous rearrangement to form an N,N-dimethylamide derivative. Cycloadditions of the diene to maleimide, N-phenylmaleimide, diethyl maleate, fumarate and butenolide, carried out in the presence of acetic anhydride,were followed by elimination of dimethylamine, afforded stable 2H-thiopyran derivatives.

Reply to Comment on “Kinetics of a Diels−Alder Reaction of Maleic Anhydride and Isoprene in Supercritical CO2”

2003 ◽  
Vol 107 (43) ◽  
pp. 9249-9249 ◽  
Author(s):  
Evgeni M. Glebov ◽  
Larisa G. Krishtopa ◽  
Victor Stepanov ◽  
Lev N. Krasnoperov
Keyword(s):  
Maleic Anhydride ◽  
Supercritical Co2 ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Kinetics Of

Asymmetric Synthesis of 3,3′-Piperidinoyl Spirooxindoles and Discovery of Stereospecific Cycloadducts as Novel Hedgehog Pathway Modulators

Synthesis ◽  
2020 ◽  
Vol 52 (21) ◽  
pp. 3140-3152
Author(s):  
Kamal Kumar ◽  
Mohammad Rehan ◽  
Jana Flegel ◽  
Franziska Heitkamp ◽  
Jorgelina L. Pergomet ◽  
...  
Keyword(s):  
Transition Metal ◽  
Small Molecules ◽  
Asymmetric Synthesis ◽  
Natural Product ◽  
Transition Metal Complexes ◽  
Alder Reaction ◽  
Diels Alder ◽  
Hedgehog Pathway ◽  
Diels Alder Reaction ◽  
Efficient Access

An enantioselective hetero-Diels–Alder reaction of alkylidene­ oxindoles and 2-aza-3-silyloxy-1,3-butadienes, catalyzed by divalent transition metal complexes with N,N′-dioxide ligands offered an efficient access to natural-product-based 3,3′-piperidinoyl spiroox­indole class of small molecules. exo-Cycloadducts formed via stereospecific cycloaddition with Z-olefin displayed potent activity in modulation of hedgehog pathway.

scholarly journals The Total Synthesis of (–)-Scabrolide a

2020 ◽  
Author(s):  
Nicholas Hafeman ◽  
Steven A. Loskot ◽  
Chris Reimann ◽  
Beau P. Pritchett ◽  
Scott C. Virgil ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

The first total synthesis of the norcembranoid diterpenoid scabrolide A is disclosed. The route begins with the synthesis of two chiral pool-derived fragments, which undergo a convergent coupling to expediently introduce all 19 carbon atoms of the natural product. An intramolecular Diels–Alder reaction and an enone-olefin cycloaddition/fragmentation sequence are then employed to construct the fused [5–6–7] linear carbocyclic core of the molecule and to complete the total synthesis.

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