The ester enolate Claisen rearrangement. Stereochemical control through stereoselective enolate formation

1976 ◽  
Vol 98 (10) ◽  
pp. 2868-2877 ◽  
Author(s):  
Robert E. Ireland ◽  
Richard H. Mueller ◽  
Alvin K. Willard
Keyword(s):  
Claisen Rearrangement ◽  
Stereochemical Control ◽  
Ester Enolate

Stereochemical control in the silyl triflate-mediated Claisen rearrangement of allylic esters

1996 ◽  
Vol 37 (17) ◽  
pp. 3005-3008 ◽  
Author(s):  
Masatada Kobayashi ◽  
Katsuhisa Masumoto ◽  
Ei-ichi Nakai ◽  
Takeshi Nakai
Keyword(s):  
Claisen Rearrangement ◽  
Stereochemical Control ◽  
Allylic Esters

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.

Asymmetric Synthesis of 2,3,6-Trisubstituted Piperidines via Baylis–Hillman Adducts and Lithium Amide through Domino Reaction

Synlett ◽  
2019 ◽  
Vol 31 (06) ◽  
pp. 600-604 ◽  
Author(s):  
Mateo M. Salgado ◽  
Alejandro Manchado ◽  
Carlos T. Nieto ◽  
David Díez ◽  
Narciso M. Garrido
Keyword(s):  
Amino Acid ◽  
Asymmetric Synthesis ◽  
Claisen Rearrangement ◽  
Domino Reaction ◽  
Amino Acid Derivative ◽  
Side Chain ◽  
Lithium Amide ◽  
Stereochemical Control ◽  
Asymmetric Michael Addition ◽  
Polysubstituted Piperidines

A convenient asymmetric synthesis of methyl (2S,3S,6R)-6-(4-fluorophenyl)-2-(4-hydroxyphenyl)-piperidine-3-carboxylate is described, starting from Baylis–Hillman adducts. The route involves a domino process: allylic acetate rearrangement, stereoselective Ireland–Claisen rearrangement and asymmetric Michael addition, which provides a δ-amino acid derivative with full stereochemical control. A subsequent chemoselective transformation of one of the side-chain groups allows an effective cyclization leading to biologically interesting polysubstituted piperidines in which the 2,6-aryl groups could be attached sequentially.

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
Sign in / Sign up

Export Citation Format

Share Document