Multicomponent Linchpin Coupling of Silyl Dithianes Employing anN-Ts Aziridine as the Second Electrophile:  Synthesis of (−)-Indolizidine 223AB

2004 ◽  
Vol 6 (9) ◽  
pp. 1493-1495 ◽  
Author(s):  
Amos B. Smith ◽  
Dae-Shik Kim
Keyword(s):  
Indolizidine 223Ab

Alkaloid Synthesis: Indolizidine 223AB (Cha), Lepadiformine (Kim), Kainic Acid (Fukuyama), Gephyrotoxin (Smith), Premarineosin A (Reynolds)

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Kainic Acid ◽  
Claisen Rearrangement ◽  
State University ◽  
University Of Oxford ◽  
Wayne State University ◽  
Peking University ◽  
Portland State University ◽  
National University ◽  
Ester Enolate ◽  
Indolizidine 223Ab

Jin Kun Cha of Wayne State University prepared (Org. Lett. 2014, 16, 6208) the allene 1 by SN2′ coupling of a cyclopropanol with a propargylic tosylate. Silver-mediated cyclization converted 1 into 2, that was reduced with diimide to the Dendrobates alka­loid indolizidine 223AB 3. Sanghee Kim of Seoul National University observed (Chem. Eur. J. 2014, 20, 17433) high diastereoselectivity in the Ireland–Claisen rearrangement of 4 to 5. The acid 5 was the key intermediate for the synthesis of the tunicate alkaloid lepadiformine 6. Tohru Fukuyama of Nagoya University also used (Eur. J. Org. Chem. 2014, 4823) an ester enolate Claisen rearrangement to set the relative and absolute configuration of 7. Pd-catalyzed cyclization then led to 8, that was carried on to the excitatory amino acid receptor agonist kainic acid 9. Gephyrotoxin 12 was so named because it incorporates structural elements from two different classes of the Dendrobates alkaloids. Martin D. Smith of the University of Oxford envisioned (Angew. Chem. Int. Ed. 2014, 53, 13826) the cascade cyclization of deprotected 10 to give, after reduction, the ketone 11. Zhen Yang of the Peking University Shenzhen Graduate School showed (Chem. Eur. J. 2014, 20, 12881) that the Rh carbene derived from 13 readily cyclized to an imine. The facial selectivity of the addition of the Grignard reagent 14 to that imine depended on the temperature of the reaction. At room temperature, 15 was formed. At low temperature, the other diastereomer predominated. Ring-closing metathesis was used for the elaboration of 15 to the Stemona alkaloid tuberostemospiroline 16. Kevin A. Reynolds of Portland State University prepared (J. Org. Chem. 2014, 79, 11674) 19 by condensation of the pyrrole 17 with the aldehyde 18. The biosyn­thetic enzyme, that they had overexpressed, oxidized 19 to the antimalarial alkaloid permarineosin A 20.

Radical Cyclization of β-Aminoacrylates:  Synthesis of (−)-Indolizidine 223AB

2000 ◽  
Vol 2 (14) ◽  
pp. 2169-2171 ◽  
Author(s):  
Eun Lee ◽  
Jeong ◽  
Sun Joon Min ◽  
Sukwon Hong ◽  
Jaehong Lim ◽  
...  
Keyword(s):  
Radical Cyclization ◽  
Indolizidine 223Ab

The norrish type I photo-cleavage of (+)-2β-ethyl-9-azabicyclo[3.3.1]nonan-3-one: A short, enantioselective formal synthesis of (−)-Indolizidine 223ab

1994 ◽  
Vol 5 (3) ◽  
pp. 317-320 ◽  
Author(s):  
Osamu Muraoka ◽  
Kazuhito Okumura ◽  
Tomomi Maeda ◽  
Genzoh Tanabe ◽  
Takefumi Momose
Keyword(s):  
Type I ◽  
Formal Synthesis ◽  
Norrish Type ◽  
Indolizidine 223Ab ◽  
Photo Cleavage

Reactions of 1,2-dehydropyrrolidin-5-one with 1,3-dienes. Synthesis of dl-gephyrotoxin 223AB

1988 ◽  
Vol 66 (5) ◽  
pp. 1163-1172 ◽  
Author(s):  
Oliver E. Edwards ◽  
Austin M. Greaves ◽  
Wing-Wah Sy
Keyword(s):  
Diels Alder ◽  
Furan Derivatives ◽  
Indolizidine 223Ab

Evidence is presented that the regiospecific and often stereospecific pseudo-Diels–Alder reactions of 1,3-dienes with N-acyl immonium salts, derived from 5-ethoxy-2-pyrrolidinone, are stepwise reactions. 6,7-Dehydroindolizidinones, unsaturated lactam esters, and new indene and furan derivatives are described. A synthesis of dl-gephyrotoxin 223AB (indolizidine 223AB) from trans-1,3-heptadiene was achieved.

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