scholarly journals Ester Enolate Claisen Rearrangement via Boat-Like Transition State

1987 ◽  
Vol 16 (2) ◽  
pp. 351-354 ◽  
Author(s):  
Harumi Uchiyama ◽  
Mika Kawano ◽  
Tsutomu Katsuki ◽  
Masaru Yamaguchi
Keyword(s):  
Transition State ◽  
Claisen Rearrangement ◽  
Ester Enolate

ChemInform Abstract: Ester Enolate Claisen Rearrangement via Boat-Like Transition State.

ChemInform ◽  
1987 ◽  
Vol 18 (42) ◽  
Author(s):  
H. UCHIYAMA ◽  
M. KAWANO ◽  
T. KATSUKI ◽  
M. YAMAGUCHI
Keyword(s):  
Transition State ◽  
Claisen Rearrangement ◽  
Ester Enolate

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.

The ester enolate claisen rearrangement. Synthesis of A C(1)C(6) erythronolide fragment

1986 ◽  
Vol 27 (4) ◽  
pp. 449-452 ◽  
Author(s):  
Steven D. Burke ◽  
Frank J. Schoenen ◽  
Charles W. Murtiashaw
Keyword(s):  
Claisen Rearrangement ◽  
Ester Enolate
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