BENZOPYRANS .30. SYNTHESIS OF SUBSTITUTED XANTHONES FROM 3-ACYL-2-METHYL-I-BENZOPYRAN-4-ONES

Authors
GHOSH CK SAHANA S PATRA A
Citation
Ck. Ghosh et al., BENZOPYRANS .30. SYNTHESIS OF SUBSTITUTED XANTHONES FROM 3-ACYL-2-METHYL-I-BENZOPYRAN-4-ONES, Tetrahedron, 49(19), 1993, pp. 4127-4134
Citations number
21
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
49
Issue
19
Year of publication
1993
Pages
4127 - 4134
Database
ISI
SICI code
0040-4020(1993)49:19<4127:B.SOSX>2.0.ZU;2-I
Abstract
The xanthone 8 results from the base catalysed self-condensation of th e chromone 1. The chromone 2 gives the xanthones 9 and 11 with sodium and DMF-POCl3 respectively, phenol 14 with NaOMe, and the pyran 22 wit h 2-thiomethylchromone 6. The enamine 16 on Vilsmeier-Haak reaction af fords the chloroxanthone 12. The pyran 15, isolated as a byproduct fro m the reaction of omega-acetyl-2-hydroxyacetophenone with HC(OEt)3-AC2 O, affords the xanthone 13 by refluxing with NaOMe in MeOH.