Cyclisation of 3-cyclopent-2-enyl-4-hydroxy[1]benzopyran-2-one

Authors
Majumdar, KC Choudhury, PK Biswas, P
Citation
Kc. Majumdar et al., Cyclisation of 3-cyclopent-2-enyl-4-hydroxy[1]benzopyran-2-one, I J CHEM B, 37(11), 1998, pp. 1197-1201
Citations number
27
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
INDIAN JOURNAL OF CHEMISTRY SECTION B-ORGANIC CHEMISTRY INCLUDING MEDICINAL CHEMISTRY
ISSN journal
03764699 → ACNP
Volume
37
Issue
11
Year of publication
1998
Pages
1197 - 1201
Database
ISI
SICI code
0376-4699(199811)37:11<1197:CO3>2.0.ZU;2-F
Abstract
3-Cyclopent-2-enyl-4-hydroxy[1]benzopyran-2-one 3 has been prepared by the reaction of 3-chlorocyclopent-2-ene 2 and 4-hydroxy[1]benzopyran-2-one 1. C ompound 3 or its acetate 4 on treatment with pyridine hydrotribromide in di chloromethane at 0-5 degrees C for 2 hr give fused furochromone 5 in 90% yi eld. Compound 5 on refluxing in 50% sulphuric acid undergoes rearrangement to furnish fused furo coumarin 7 in 87% yield.