- A novel synthesis of coumarins employing triphenyl(α-carboxymethylene)phosphorane imidazolide as a C-2 synthon
-
A novel one-pot synthesis of coumarins via intramolecular Wittig cyclization from the reaction of phenolic compounds containing ortho-carbonyl group and triphenyl(α-carboxymethylene)phosphorane imidazolide is described.
- Upadhyay, Puspesh K.,Kumar, Pradeep
-
scheme or table
p. 236 - 238
(2009/05/11)
-
- On the Spectral Properties of Some Fused 4-Methylcoumarins
-
Preparations of the ring-fused 4-methylcoumarins 2-10 were reexamined, and the nuclear magnetic resonance (NMR), ultraviolet (UV) and fluorescence spectral characteristics were determined.Fluorescence properties were found to be sensitive to the type and the position of the ring fused to the parent 4-methylcoumarin 1.The angularly benzo-fused 3 was highly flurescent, whereas the linearly benzo-fused 4 and the pyrono-fused 7 and 9 were only weakly fluorescent.Keywords benzocoumarin; pyronocoumarin; 1H-NMR; UV; fluorescence spectrum; fluorescence quantum yield
- Maruyama, Junko,Ito, Keiichi
-
p. 1178 - 1182
(2007/10/02)
-
- A Fresh Look at the Pechmann Condensation and Duff Rection with β-Naphthol
-
Pechmann condensation of β-naphthol with ethyl acetoacetate in the presence of anhydrous aluminium chloride gives, besides two known compounds, 4-methyl-6,7-benzocoumarin and 3-methyl-9-hydroxyphenalen-1-one (I).The Duff reaction of β-naphthol gives the new compounds 1,3-diformyl-2-naphthol and 2-formyl-2,3-dihydro-1H-naphth-oxazine (II) and the known 2,2'-dihydroxy-1,1'-binaphthylmethane.Compound (II) exists as a mixture of rotamers.
- Kostova, I. N.,Pardeshi, N.,Rangaswami, S.,Lee, Yue-Wei
-
p. 859 - 862
(2007/10/02)
-