Studies on the Synthesis of Furocoumarins. Part-XXX. A Reinvestigation of Claisen Rearrangement of 7-Cinnamyloxy-4-methylcoumarin
| Main Authors: | S. S. MADHAVA RAO, K. N. TRIVEDI |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1992
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6002891 |
Daftar Isi:
- Department of Chemistry, Faculty of Science, M. S. University of Baroda, Baroda-390 002 Manuscript received 24 October 1991, accepted 23 March 1992 7-annamylozy. 8-methylcoumarin on Claisen migration gave three products. trans-3, 7-dimethyl 2-phenyl-2 3- dihydrofurel-[2,3-b]Abenzopyran 5[H]-one (la), 7 hydroxy 4-methyl 8-(1'-phenylprop-1'-ene)coumarin (1e) and 7 by drozy 4 methyl 6 (1' phenyiprop 2 -ene)coumariu (if) le and If on cyclisation with H2SO4 gave 2b and 3a respectively 2a 2b and 3a on dehydrogenation with either DDQ in dry benzene or Pd C (10 4,) in diphenyl ether gave 4a 4b and 5b respectively. In a similar way 2,5,9-trimethy1-3 phenylfuro[3,2-g]benzopyran 7[H] one (5c) was also synthesised. Structures of the compounds were confirmed by 'H nmr spectra and cis and trans-stereo-chemistry of dibydrofurocoumarins was established by nOe difference spectra.