531-59-9Relevant articles and documents
Applied photochemistry - Light controlled perfume release
Derrer, Samuel,Flachsmann, Felix,Plessis, Caroline,Stang, Melanie
, p. 665 - 669 (2007)
Ambient light is one of the most suitable available trigger conditions for the release of covalently bound volatile odorants in home- and laundry-care applications. We report on three complementary classes of light-cleavable fragrance precursors, covering the controlled release of odorants with a wide range of functional groups. o-Hydroxy cinnamates 1 undergo a UV-induced double bond isomerization followed by transesterification to release coumarin and a fragrance alcohol of choice. α-Alkoxyacetophenones 10 and α,α-dialkoxyacetophenones 12 undergo Norrish type II fragmentations upon UV-irradiation, thereby releasing one or two equivalents of fragrant aldehydes, respectively. Finally, photoexcited Xanthenoic esters 22 undergo fragmentation to release reactive acyl radicals, which further cyclize onto internal olefins to form perfumery lactones of various ring sizes. Schweizerische Chemische Gesellschaft.
ACCUMULATION OF COUMARINS IN ELICITOR-TREATED CELL SUSPENSION CULTURES OF AMMI MAJUS
Hamerski, Daria,Beier, Ross C.,Kneusel, Richard E.,Matern, Ulrich,Himmelspach, Karl
, p. 1137 - 1142 (1990)
Heterotrophic cell suspension cultures were initiated from hypocotyls of young Ammi majus L. seedlings.When these cultures were propagated continuously in the dark, they produced only traces of the coumarin umbelliferone.Upon addition of fungal cell wall fractions, i.e. a skleroglucan or an elicitor from either Phytophthora megasperma f. sp. glycinea or Alternaria carthami, the cells excreted large amounts of umbelliferone in addition to isopimpinellin, (S)-marmesin, (R)-ammirin, umbelliferone--ether and umbelliferone--ether.The last two compounds are new compounds and appear to be derived from 7-O-prenylumbelliferone, a coumarin that has been identified in from other plants.The Phytophthora-elicitor was the most effective inducer of coumarin accumulation.When cultures which had been elicited for 3 hr were pulsed with L-14C>phenylalanine for 7 hr, all the coumarins and an additional, still unidentified compound in the extracts were labelled efficiently.Our results suggest that A. majus cells are particularly suitable for biosynthetic studies on various coumarins as well as for regulatory studies of the inhibition of coumarin phytoalexin accumulation.
Cycloreversion performance of coumarin and hetero-coumarin dimers under aerobic conditions: Unexpected behavior triggered by UV-A light
Bieniek, Nikolai,Hampp, Norbert,Inacker, Sebastian
, p. 17703 - 17712 (2021/08/30)
Photochemical [2+2]-cycloadditions of coumarin-like monomers are the textbook paradigms of photo-formation and photo-cleavage reactions. The electronic conjugation length of monomers and dimers is quite different which results in almost fully separated UV/Vis absorption bands in the UV-A and UV-C. This feature enables the selective light-controlled conversion between monomeric and dimeric forms by the choice of the appropriate wavelengths. Several applications are based on this kind of reversible photo linker without absorption in the visible range. But which is the best molecule from the coumarin family for such an application? Within this study, we compared the photochemical cleavage behavior of twelve coumarin-type cyclobutane dimers. In particular, the influence of isomer structure and substitution pattern was studied. Two dimers with an unexpected high quantum yield for cyclobutane cleavage were identified. This behavior is explained through the differing ring strain of the cyclobutane moiety. Electron donating substitutions of the framework, e.g. with a methoxy function (+M-effect), leads to a decreased oxidation potential, making the dimers sensitive towards oxidative dimer splitting. This result disqualifies coumarins, e.g. attached to a polymer backbone via an ether bond, often in the 7-position, because of their instabilities and side reactions in an aerobic environment. The methylated dimers (+I-effect) show excellent stability towards this undesired side reaction as well as a high cleavage efficiency upon irradiation with 265 nm. All twelve investigated dimers are ranked for their quantum efficiency and rate constant for cleavage at 265 nm, as well as their oxygen tolerance. As the most promising derivative within our scope for applications the methylated coumarin dimer was identified.
Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2 H-Chromenes
Cervi, Aymeric,Vo, Yen,Chai, Christina L. L.,Banwell, Martin G.,Lan, Ping,Willis, Anthony C.
, p. 178 - 198 (2020/12/22)
Methods are reported for the efficient assembly of a series of phenol-derived propiolates, including the parent system 56, and their Au(I)-catalyzed cyclization (intramolecular hydroarylation) to give the corresponding coumarins (e.g., 1). Simple syntheses of natural products such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal X-ray analysis. A related process is described for the conversion of propargyl ethers such as 156 into the isomeric 2H-chromene precocene I (159), a naturally occurring inhibitor of juvenile hormone biosynthesis.