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NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
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Research Journals >
Indian Journal of Chemistry -Section B (IJC-B) >
IJC-B Vol.44B [2005] >
IJC-B Vol.44B(12) December 2005] >
| Title: | Synthesis of isoflavones containing naturally occurring substitution pattern by oxidative rearrangement of respective flavanones using thallium(III) p-tosylate |
| Authors: | Singh, Om V
Muthukrishnan, M
Sunderavadivelu, M |
| Keywords: | Thallium(III) p-tosylate
oxidative rearrangement
isoflavones
flavanones
2,3-aryl migration |
| Issue Date: | Dec-2005 |
| Publisher: | CSIR |
| IPC Code: | Int.Cl.7 C 07 D |
| Abstract: | Claisen condensation of substituted 2'-hydroxyacetophenones
1a-c with aromatic aldehydes affords respective substituted 2'-hydroxychalcones
2a-n which on base catalyzed cyclization in pyridine : methanol : water
(1:1:1) give respective flavanones 3a-n. The oxidative rearrangement of
flavanones with thallium (III) p-tosylate
furnishes respective isoflavones 4a-n in overall 62-72% yields starting
from 1. The present methodology has been successfully applied for the
synthesis of naturally occurring isoflavones such as di-O-methyldaidzein
4a, cabruvin 4b, pseudobabtigenin methylether 4d, 5,7-dimethoxyisoflavone
4f, 5,7,4'-trimethoxyisoflavone 4g, derrustone 4i, 7,8,3',4'-tetramethoxyisoflavone
4l, purpuranin-A 4m and 7,8,3',4',5'-pentamethoxyisoflavone 4n and thus the first synthesis of 4n
is reported. |
| Page(s): | 2575-2581 |
| ISSN: | 0975-0983(Online); 0376-4699(Print) |
| Source: | IJC-B Vol.44B(12) December 2005]
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