Synthetic Furocoumarins. I. A New Synthesis of Methyl-substituted Psoralenes and Isopsoralenes

A New Synthesis of Angelicin from 7‐Hydroxycoumarin via C‐Propenation‐O‐Vinylation and Ring‐Closing Metathesis

“…For example, both compound 3, and compound 4 are coincident with the spectral data reported in the previous studies. 16,17 However, compound 5, which was paid no attention in the related Claisen rearrangement, 16,17 exhibited the same spectral data in both proton-NMR and carbon-13 NMR reported by different approaches. 19 Subsequently 8-allyl-7-hydroxycoumarin (3) dissolved in dry acetone was reacted with excess 1,2-dichloroethane under mild reflux in the presence of anhydrous K 2 CO 3 for 8 h, to undergo monochloroethylation to give 8-allyl-7-(2-chloroethoxy)coumarin (6) as the sole product, in yields of 92%.…”

“…rangement of 7-allyloxycoumarin (2) have been reported, such as heating to reflux in N,N-diethylaniline in a closed vessel, and in refluxing ethylene glycol. However only 8allyl-7-hydroxycoumarin (3) was obtained and reported in 84% yields or in 94% crude yields in the condition of refluxing in N,N-diethylaniline 16 or in a closed vessel, 17 respectively. On the other hand, not only 8-allyl-7-hydroxycoumarin (3) in 70% yields but also 6-allyl-7-hydroxycoumarin (4) in 20% yields was obtained if in refluxing ethylene glycol.…”

Synthesis of Highly Z‐Selective Coumarin Annulated Dioxocine, Dioxacindione and Macrocycles Using Grubbs’ Second‐Generation Catalyst

“…8‐allyl‐7‐hydroxy‐4‐methylcoumarins ( 3a‐c ) prepared from the allylaion of 7‐hydroxy‐4‐methylcoumarins ( 1a‐c ), to give 2a‐c , followed by their regiospecific aromatic claisen rearrangement under the thermal conditions in refluxing diphenyl ether . 8‐allyl‐7‐hydroxy‐4‐methylcoumarins ( 3a‐c ) was then dimerisezed between their phenolic OH groups using aliphatic linkers to give 4a‐h .…”

Synthesis and biological evaluation of fused oxepinocoumarins as free radicals scavengers

“…137-139°C) and 8-allyl-7-hydroxy-2H-chromene-2 -one (3a) (1.45 g, 68%), m.p. 164-166°C (DCM-CH 3 OH) (lit 46 . 165-166°C).…”