Three new natural coumarin substances 1, 2 and 3 (derivatives of 2',2'-dimethyl-3',4'-dihydroxydihydropyrano-5',6':6,7-coumarin) were isolated from the roots and fruits of Peucedanum arenarium W.K. On the basis of the spectral data from UV, IR, and NMR spectra of coumarin 1, named peuarenarine, it was assumed, that, it is an ester of 2',2'-dimethyl-3',4'-dihydroxy-dihydropyrano5',6' :6,7-coumar...

Stereoselective photodimerization of coumarin and its derivatives in supra-molecular systems is reviewed. The enantioselective photodimerization of coumarin and thiocoumarin in inclusion crystals with optically active host compounds is also described.

2-Dimethyl-2H-Chromenes, Coumarin Derivatives, Phase-Transfer Catalysis 2,2-Dimethyl-5H-pyrano(3,2-c)-l-benzopyrano-5-one(2) and 4H-2,3-dihydro-3-methyl-2methylene-furan-l-benzopyran-4-one (3), two new coumarin derivatives were synthesised from 4-hydroxycoumarin by treating with 3-chloro-3-methylbut-l-yne and 3-chlorobut-l-yne respectively, both reactions progressing via the phase-transfer cata...

The use of coumarin caged molecules has been well documented in numerous photocaging applications including for the spatiotemporal control of Cre-estrogen receptor (Cre-ERT2) recombinase activity. In this article, we report that 4-hydroxytamoxifen (4OHT) caged with coumarin via a conventional ether linkage led to an unexpected photo-Claisen rearrangement which significantly competed with the re...

Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro antimicrobial activity, in a standard disk diffusion assay, against thirteen str...

Z. Naturforsch. 55c, 5 2 8 -5 3 3 (2000); received April 5/April 20. 2000 Pelargonium Species, Umckaloabo, Coumarins, Oxygenation Pattern The coumarin patterns of Pelargonium sidoides DC. and Pelargonium reniforme CURT., forming the origin of the herbal medicine “umckaloabo”, were analysed and compared for therapeutic equivalence. For both species, members of triand tetraoxygenated coumarins al...

Abstract Coumarin and its nitrogen analogue 1-aza coumarin are a class of lactones lactams, respectively, which indispensable heterocyclic units to both chemists biochemists. 1-Aza derivatives, ultimately metabolize as the corresponding 8-hydroxy coumarins in biological system therefore found be very good anti-inflammatory, anti-cancer, analgesic agents. A series hybrid substituted azacoumarin-...

An efficient synthesis of some novel coumarin derivatives via 1, 4- Michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (CSA) under solvent free conditions is described. The corresponding Michael addition products were obtained in good to excellent yield. The synthesized compounds were screened for their antibacterial activity against E. coli, S. aureus and an...

An efficient synthesis of some novel coumarin derivatives via 1, 4- Michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (CSA) under solvent free conditions is described. The corresponding Michael addition products were obtained in good to excellent yield. The synthesized compounds were screened for their antibacterial activity against E. coli, S. aureus and an...

An unexpected transformation of 2H-chromene-3-carboxaldehydes to coumarin derivatives, mediated by NHC, is reported.