- Benzopyrones. Part 19. Synthesis and some Reactions of Ethyl 3-Bromo-4-oxochromen-2-carboxylate
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The product of the condensation of o-hydroxyacetophenone and diethyl oxalate, ethyl 2-hydroxy-4-oxochroman-2-carboxylate (13), slowly and partially isomerises in solution to the phenolic ketone (16), but in the presence of mineral acid, it is rapidly dehydrated directly to ethyl 4-oxochromen-2-carboxylate (2; R = Et).Bromination of the oxochroman (13) gave a 72:28 mixture of epimeric 3-bromo-esters.The major isomer (trans-OH,H) was readily dehydrated to give the title compound which contains a reactive bromine atom.
- Bevan, Peter S.,Ellis, Gwynn P.
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p. 1705 - 1709
(2007/10/02)
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