91029-31-1Relevant academic research and scientific papers
Total Synthesis of Isorosthin L and Isoadenolin I
Ao, Junli,Sun, Chao,Chen, Bolin,Yu, Na,Liang, Guangxin
, (2022/01/20)
Total syntheses of two Isodon diterpenes, isorosthin L and isoadenolin I, are reported. The synthetic strategy features a quick assembly of two simple building blocks through a diastereoselective intermolecular aldol reaction and a subsequent radical cyclization for efficient construction of a rather complex advanced intermediate bearing a quaternary stereocenter present in all Isodon diterpenes. Oxidative cleavage of the C?C bond in the cyclopentane enabled the conversion to a lactone moiety which is desired for the construction of the molecular skeleton through reductive coupling with an aldehyde carbonyl group.
Total synthesis of viridicatumtoxin B and analogues thereof: Strategy evolution, structural revision, and biological evaluation
Nicolaou,Hale, Christopher R. H.,Nilewski, Christian,Ioannidou, Heraklidia A.,Elmarrouni, Abdelatif,Nilewski, Lizanne G.,Beabout, Kathryn,Wang, Tim T.,Shamoo, Yousif
, p. 12137 - 12160 (2014/11/08)
The details of the total synthesis of viridicatumtoxin B (1) are described. Initial synthetic strategies toward this intriguing tetracycline antibiotic resulted in the development of key alkylation and Lewis acid-mediated spirocyclization reactions to form the hindered EF spirojunction, as well as Michael-Dieckmann reactions to set the A and C rings. The use of an aromatic A-ring substrate, however, was found to be unsuitable for the introduction of the requisite hydroxyl groups at carbons 4a and 12a. Applying these previous tactics, we developed stepwise approaches to oxidize carbons 12a and 4a based on enol- and enolate-based oxidations, respectively, the latter of which was accomplished after systematic investigations that revealed critical reactivity patterns. The herein described synthetic strategy resulted in the total synthesis of viridicatumtoxin B (1), which, in turn, formed the basis for the revision of its originally assigned structure. The developed chemistry facilitated the synthesis of a series of viridicatumtoxin analogues, which were evaluated against Gram-positive and Gram-negative bacterial strains, including drug-resistant pathogens, revealing the first structure-activity relationships within this structural type.
Total synthesis and structural revision of viridicatumtoxin B
Nicolaou,Nilewski, Christian,Hale, Christopher R. H.,Ioannidou, Heraklidia A.,Elmarrouni, Abdelatif,Koch, Lizanne G.
, p. 8736 - 8741 (2013/09/12)
Will the real viridicatumtoxin B please stand up: The total synthesis of viridicatumtoxin B resulted in its structural revision and opens the way for analogue construction and biological evaluation of this complex tetracycline-like antibiotic. The highly convergent strategy employed allows for swift construction of the entire carbocyclic framework of the molecule. Copyright
Improved synthesis of methyl 3-oxo-2,6,6-trimethylcyclohex-1-ene-1- carboxylate, an A-ring intermediate for (±)strigol
Qianchao,Shiqing, Pi,Xinzhi, Chen
, p. 494 - 496 (2008/09/21)
Methyl 3-oxo-2,6,6-trimethylcyclohex-1-ene-1-carboxylate was synthesised over eight steps from the starting material of citral instead of α-ionone. KMnO4, HC(OEt)3 and O2/TEMPO/CuCl were substituted for NaIO4, CH3I and pyridinium chlorochromate, respectively. Every step was simplified and gave a 48% overall yield. The procedure is suitable for large scale production.
Chemical studies on crude drug processing. IX. On the constituents of rehmanniae radix. (3). Absolute stereostructures of rehmaionosides A, B, and C, and rehmapicroside, biologically active ionone glucosides and a monoterpene glucoside isolated from Chine
Yoshikawa,Fukuda,Taniyama,Kitagawa
, p. 41 - 47 (2007/10/03)
Following the characterization of the iridoid and iridoid glycoside constituents in Chinese Rehmanniae Radix, the dried root of Rehmannia glutinosa LIBOSCH. [Kan-jio in Japanese], we investigated the structures of biologically active ionone glucosides, re
Synthesis and biological evaluation of A-ring analogs of the natural germination stimulant strigol
Mangnus, E. M.,Zwanenburg, B.
, p. 155 - 159 (2007/10/02)
An A-ring-derived analog of the natural germination stimulant, Strigol (1), has been prepared from citral in an unambiguous manner.This analog, 2, a γ-hydroxy aldehyde for which a high stimulant activity was claimed in the literature, has been re-evaluate
NORCAROTENOIDS OF REHMANNIA GLUTINOSA VAR. HUEICHINGENSIS
Sasaki, Hiroshi,Morota, Takashi,Nishimura, Hiroaki,Ogino, Tatsunori,Katsuhara, Takao,et al
, p. 1997 - 2001 (2007/10/02)
Two new norcarotenoids named trihydroxy-β-ionone and sec-hydroxyaeginetic acid, together with three known compounds, have been isolated from the steamed roots of Rehmannia glutinosa var. hueichingensis.Their structures were determined by chemical and spectral studies, and confirmed by X-ray analysis of trihydroxy-β-ionone acetate. Key Word Index: Rehmannia glutinosa var. hueichingensis; Scrophulariaceae; roots; norcarotenoids; trihydroxy-β-ionone; dihydroxy-β-ionone; sec-hydroxyaeginetic acid; aeginetic acid; rehmapicrogenin; X-ray analysis.
