- Nitration versus nitrosation chemistry of menthofuran: Remarkable fragmentation and dimerization pathways and expeditious entry into dehydromenthofurolactone
-
(Chemical Equation Presented) The reaction chemistry of menthofuran (1), a toxic furan terpenoid from various mint oils, with nitric acid and nitrous acid has been investigated. Treatment of 1 with nitric acid afforded a 1:1 mixture of the bisfuran derivatives 5 and 6, resulting from the unexpected cleavage of the furan into two carbonyl fragments (3-methylcyclohexanone and hydroxyacetone) and their subsequent trapping by unreacted 1. Under conditions of high dilution, the nitrofuran derivative 7 was formed instead as the major reaction product. During investigation of this chemistry, it was found that oxidation of 1 with DDQ led to the important fragrant monoterpenoid 4 [dehydromenthofurolactone (anhydro Woodward-Eastman lactone)] in 44% yield. Exposure of 1 to nitrite ions at pH 3 afforded a completely different type of products, encompassing the known lactone 14, the lactam 15, and the remarkable dimer 16, bearing a N-hydroxy-2-pyrrolinone moiety linked to a nitrooximinofuran unit by an oxygen bridge. By using a combined spectroscopic and DFT approach, the constitution and configuration of 16 could be determined. These results fill a gap in the chemistry of furan compounds and describe routes to menthofuran-derived scaffolds of potential synthetic and biomedical relevance.
- De Lucia, Maria,Mainieri, Francesco,Verotta, Luisella,Maffei, Massimo,Panzella, Lucia,Crescenzi, Orlando,Napolitano, Alessandra,Barone, Vincenzo,Appendino, Giovanni,D'Ischia, Marco
-
-
Read Online
- TiCl4-Et3N-mediated one-step synthesis of γ-alkylidenebutenolides from ketones: Application to natural product synthesis
-
TiCl4-Et3N-mediated condensation of ketones with methyl pyruvate afforded γ-alkylidene butenolides via a tandem cross-aldol addition/dehydroxylation/intramolecular lactonization process in one-pot. The application of the methodology to the straightforward synthesis of elem-1,3,7,8-tetraen-8,12-olide, chloranthalactone A, and dehydromenthofurolactone, is demonstrated.
- Li, Xingyi,Wang, Yanhong,Fu, Kai,Hu, Zhiyong,Li, Zhichun,Ma, Wenbing,Xun, Miao-Miao,Yuan, Changchun
-
p. 2056 - 2062
(2020/02/25)
-
- One-step synthesis of furan rings from α-isopropylidene ketones mediated by iodine/DMSO: An approach to potent bioactive terpenes
-
The system I2/dimethyl sulfoxide mediates the one-step transformation of α-isopropylidene ketones into furan rings following a biomimetic approach. This methodology has been used for the synthesis of terpene furans such as mintfurane, curzerene, atractylon, and isoatractylon, all of them possessing interesting biological activities. The synthesis of linderazulene directly from 4,5-epoxygermacrone via a cascade reaction shows the potential of this protocol. Additionally, this compound proved to show significant ixodicidal activity.
- Salihila, Jonida,Silva, Lúcia,Pérez Del Pulgar, Helena,Quílez Molina, Ana,González-Coloma, Azucena,Olmeda, A. Sonia,Quílez Del Moral, José F.,Barrero, Alejandro F.
-
p. 6886 - 6894
(2019/06/14)
-
- A New Keto-alcohol, (-)-Mintlactone, (+)-isoMintlactone and Minor Components in Peppermint Oil
-
Eighty-one constituents were newly identified from the oil of Mentha piperita L., including a new keto-alcohol, (-)-mintlactone and (+)-isomintlactone.They were determined by spectral data and syntheses to be 4-hydroxy-4-methyl-2-cyclohexen-1-one (8), (6R
- Takahashi, Katsuhiro,Someya, Taichi,Muraki, Shigeru,Yoshida, Toshio
-
p. 1535 - 1544
(2007/10/02)
-