145801-08-7Relevant academic research and scientific papers
Studies on the Synthesis of Furocoumarins. Part XXX. A Reinvestigation of Claisen Rearrangement of 7-Cinnamyloxy-4-methylcoumarin
Rao, S. S. Madhava,Trivedi, K. N.
, p. 203 - 206 (2007/10/02)
7-Cinnamyloxy-1-methylcoumarin on Claisen migration gave three products: trans-3,7-dimethyl-2-phenyl-2,3-dihydrofurobenzopyran-5-one (2a), 7-hydroxy-4-methyl-8-(1'-phenylprop-1'-ene)coumarin (1e) and 7-hydroxy-4-methyl-6-(1'-phenylprop-2-ene)coumarin (1f). 1e and 1f on cyclisation with H2SO4 gave 2b and 3a respectively. 2a , 2b and 3a on dehydrogenation with either DDQ in dry benzene or Pd/C (10percent) in diphenyl ether gave 4a, 4b and 5b, respectively.In a similar way 2,5,9-trimethyl-3-phenylfurobenzopyran-7-one (5c) was also synthesised.Structures of the compounds were confirmed by 1H nmr spectra and cis and trans-stereochemistry of dihydrofurocoumarins was established by nOe difference spectra.
