<b>A Mechanistically Significant Intermediate in the Lumisantonin to Photosantonic Acid Conversion</b>

Chapman, O. L.; Englert, Leo F.

doi:10.1021/ja00902a037

Cited by 39 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The infrared spectrum of synthesized compound 3 showed a broad band at 3445 cm À1 associated with OeH stretching and two intense bands at 1768 and 1699 cm À1 , corresponding to carbonyl stretching of the lactone and ketone, respectively. The 1 [36], the formation of the acid 2 involves the participation of the intermediates 4 and 9. The guaianolide 3, however, is formed by water nucleophilic attack on the carbon C-10 of compound 1 [37].…”

Section: Synthesismentioning

confidence: 99%

Synthesis of novel α-santonin derivatives as potential cytotoxic agents

Arantes

Barbosa

Maltha

et al. 2010

European Journal of Medicinal Chemistry

View full text Add to dashboard Cite

Ten novel α-santonin derivatives have been synthesized as cytotoxic agents. The in vitro antitumor activity of these compounds has been evaluated against cancer cells lines. Structure-activity relationships indicate that α-methylene-γ-lactone and endoperoxide functionalities play important roles in conferring cytotoxicity. The compounds 2-4, possessing the α-methylene-γ-lactone group showed IC50 values between 5.70 and 16.40 μM. Mixture of isomers 5 and 6, with the α-methylene-γ-lactone and endoperoxide functionalities, displayed the greatest activity, with IC50 values between 1.45 and 4.35 μM. The biological assays conducted with normal cells revealed that the compounds 2, 5 and 6 are selective against cancer cells lines tested. Bioactive lactones described herein and in our previous report did not cause disruption of the cell membrane in mouse erythrocytes.

show abstract

Section: Synthesismentioning

confidence: 99%

Synthesis of novel α-santonin derivatives as potential cytotoxic agents

Arantes

Barbosa

Maltha

et al. 2010

European Journal of Medicinal Chemistry

View full text Add to dashboard Cite

show abstract

“…Esse resultado está de acordo com a proposta de que 11 é intermediário na transformação da α-santonina em 12. 24,25 No espectro de massas do composto 12 foi observado o pico do íon molecular em m/z = 246, em conformidade com a fórmula molecular C 15 H 18 O 3 . O espectro de RMN de 13 C apresentou sinais em δ = 123,5, 125,3, 138,7 e 152,3 referentes aos carbonos sp 2 , além de sinais em δ = 179,3 e 206,0, correspondentes às carbonilas da lactona e da cetona, respectivamente.…”

unclassified

Síntese e avaliação da atividade fitotóxica de derivados da α-Santonina

Alvarenga¹,

Barbosa²,

Saliba³

et al. 2009

Quím. Nova

View full text Add to dashboard Cite

Recebido em 13/5/08; aceito em 12/9/08; publicado na web em 2/2/09 SYNTHESIS AND EVALUATION OF THE PHYTOTOXIC ACTIVITY OF α-SANTONIN DERIVATIVES. Mixtures of α-Santonin and various solvents were irradiated by either high or low pressure mercury lamps. The photochemical reactions afforded lumisantonin (11) (76% in acetonitrile), (3S,3aS,9bS)-3,6,6-trimethyl-3,3a,4,5-tetrahydronafto[1,2-b]furan-2,7(6H,9bH)dione (12) (100% in acetonitrile), 10α-acetoxy-3-oxo-1,7αH,6,11βH-guaia-4-en-6,12-olide (8) (26% in acetic acid), 10α-hydroxy-3-oxo-1,7αH,6,11βH-guaia-4-en-6,12-olide (10) (32%) and (E)-3-((3S,3aS,7aS)-3-methyl-2-oxo-6-(propan-2-ylidene)hexahydrobenzofuran-7-(7aH)-ylidene)propanoic acid (9) (44%) (in water/ acetic acid 1:1, v/v). Lactone 12 was also prepared by irradiation of lumisantonin in diethyl ether. Lactones 8 and 10 were converted, respectively, into the 10α-acetoxy-3β-hydroxy-1,7αH,6,11βH-guaia-4-en-6,12-olide (13) (87%) and 3β,10α-dihydroxy-1,7αH,6,11βH-guaia-4-en-6,12-olide (14) (75%) by sodium borohydride reduction. The effects of the compounds on the development of radicle of Sorghum bicolor and Cucumis sativus were evaluated.

show abstract

“…Rearrangement of the cross-conjugated dienone present in 125 takes place upon irradiation to form lumisantonin (126), which provides the starting point for further transformations, for example, in aqueous solution towards photosantonic acid (127) [46] or in acetic acid towards the 5,7,5-membered ring system of guaianolides 128. [47] Biomimetic Synthesis of Absinthin Absinthin (133) was isolated in 1953 by Herout et al [48] as a dimeric guaianolide from Artemisia absinthium.…”

Section: Hemi-synthesis Starting From Santoninmentioning

confidence: 99%

Synthesis of Biologically Active Guaianolides with a trans‐Annulated Lactone Moiety

Schall

Reiser

2008

Eur J Org Chem

View full text Add to dashboard Cite

The biosynthetic pathways of sesquiterpene lactones are described in conjunction with recent developments in the total syntheses of various biologically active guaianolides. Different strategies towards the 5,7,5‐membered ring system are highlighted. Oxidative diol cleavages, aldol reactions, and intramolecular cyclopropanations were used as key reactions to construct the racemic guaianolide core system. Radical cyclizations, as well as ring closing metathesis, were successfully applied in asymmetric approaches. Biomimetic reactions were also applied as versatile tools for the construction of these highly complex natural products.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

show abstract

A Mechanistically Significant Intermediate in the Lumisantonin to Photosantonic Acid Conversion

Cited by 39 publications

References 0 publications

Synthesis of novel α-santonin derivatives as potential cytotoxic agents

Synthesis of novel α-santonin derivatives as potential cytotoxic agents

Síntese e avaliação da atividade fitotóxica de derivados da α-Santonina

Synthesis of Biologically Active Guaianolides with a trans‐Annulated Lactone Moiety

Contact Info

Product

Resources

About