Synthesis of 2,3-<i style="">trans</i>-3,4-<i style="">trans</i>-2-aryl-3-alkyl/aryl chroman-4-ols

618-621-Alkyl chalcones 3a-d on acid catalyzed cyclization give a mixture of (±) trans and (±) cis 2-aryl-3-alkylchroman-4-ones. cis 4a-d are converted to trans 5a-d by epimerization with dil. alkali. a-Aryl chalcones 3e-h on acid catalyzed cyclization give (±) trans 2,3-diaryl-chroman-4-ones 5e-h. On NaBH4 reduction 5a-h give (±) 2,3-trans-3,4-trans-2-aryl-3-alkyl/aryl- chroman-4-ols 6a-h

A convenient synthesis of ethyl furo[2,3-<i style="">h</i>] flavone/chromone-8-carboxylates

1671-1676The reaction of 8-formyl-7-hydroxyflavones/chromone 2a-i with diethyl bromomalonate in the presence of K2CO3/toluene and tetrabutylammoniumbromide (TBAB) as a phase transfer catalyst under nitrogen atmosphere affords ethyl furo[2,3-h]flavone-8-carboxylates 3a-h and ethyl 2-(2'-furyl)-3-methyl-furo[2,3-h]chromone-8-carboxylate 3i (Method A). The reaction of 2a-i with ethyl bromo acetate in powdered K2CO3/dioxane affords the same products 3a-i (Method B)

Chromone: A valid scaffold in medicinal chemistry

Chromones are a group of naturally occurring compounds that are ubiquitous in nature, especially in plants. The word chromone is derived from the Greek word chroma, meaning “color”, which point out that many chromone derivatives can exhibit a diversity of colors.This work was supported by the Foundation for Science and Technology (FCT), Portugal (projects PTDC/QUI-QUI/113687/2009 and PEst-C/QUI/UI0081/2013). A.G. (SFRH/BD/43531/2008) and M.J.M. (SFRH/BD/61262/2009) thank FCT for grants