21293-20-9Relevant academic research and scientific papers
A Concise Enantioselective Approach to Quassinoids
Thomas, William P.,Pronin, Sergey V.
, p. 118 - 122 (2022/01/08)
A synthetic approach to quassinoids is described. The route to the tetracyclic core relies on an efficient and selective annulation between two unsaturated carbonyl components that is initiated by catalytic hydrogen atom transfer from an iron hydride to an alkene. Application of this strategy allows for enantioselective synthesis of quassin, which is prepared in 14 steps from commercially available starting material.
Total synthesis of d,l-quassin
Stojanac, Nada,Valenta, Zdenek
, p. 853 - 855 (2007/10/02)
The completion of the total synthesis of d,l-quassin 1 is described.Key steps are a facile intramolecular acylation of a protected cyanohydrin carbanion (4 -> 5), a selective deprotonation with trioctyl methyl ammonium hydroxide leading to the removal of HCN from 8, and the unusual sequence 5 -> 12 in which the ring C enol ether of 5 is converted selectively into ring C diosphenol of 12. Key words: quassin, synthesis, selective base, diophenols, acylation.
ON EQUILIBRATION OF QUASSIN AND 4-EPIQUASSIN
Stojanac, Nada,Valenta, Zdenek
, p. 2298 - 2305 (2007/10/02)
Equilibration of quassin and 4-epiquassin is described.Various quassin derivatives are characterized and their relationship to quassin (I) is discussed.A regioselective deprotonation is achieved in quassin and 4-epiquassin (III) by the introduction of a diosphenolate grouping which makes a potentially acidic H-atom unavailable for attack by base.
QUASSINOIDS: TOTAL SYNTHESIS OF DL-QUASSIN
Vidari, Giovanni,Ferrino, Sergio,Grieco, Paul A.
, p. 3539 - 3548 (2007/10/02)
The total synthesis of quassin (1), the major constituent of quassia wood, is described in racemic form.The synthesis features the Lewis acid catalyzed intermolecular Diels-Alder reaction between dienophile 8 and ethyl (E)-4-methyl-3,5-hexadienoate (9).Di
SYNTHETIC STUDIES ON QUASSINOIDS: A STEREOSELECTIVE CONSTRUCTION OF THE PICRASANE SKELETON
Miyaji, Katsuaki,Nakamura, Toshio,Hirota,, Hiroshi,Igarashi, Michito,Takahashi, Takeyoshi
, p. 5299 - 5302 (2007/10/02)
12β-Hydroxypicrasan-3-one, a compound having the correct relative stereochemistry of all the six ring-juncture chiral centers of the picrasane skeleton, was synthesized from a known tricyclic compound, using the orthoester Claisen rearrangement and lead tetraacetate oxidation as key reactions.
QUASSINOIDS. ISOLATION FROM SOULAMEA MUELLERI AND STRUCTURES OF 1,12-DI-O-ACETYL SOULAMEANONE AND Δ2-PICRASIN B. X-RAY ANALYSIS OF SOULAMEANONE
Polonsky, Judith,Tri, Mai Van,Varon, Zoia,Prange, Thierry,Pascard, Claudine,et al.
, p. 2983 - 2988 (2007/10/02)
The structures of soulameanone, 1,12-di-O-acetyl soulameanone and Δ2-Picrasin B, new quassinoids from Soulamea muelleri (Simaroubaceae), were determined by spectrometric methods and chemical correlation, and that of Soulameanone confirmed by single crystal X-ray analysis.
