• Journal of the Korean Society of Industry Convergence
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• v.9 no.4
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• pp.331-336
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• 2006

An efficient synthesis of 3,4-dihydro-2H-pyrans is achieved by $Ag_2CO_3$/celite mediated reaction of 1,3-dicarbonyl compounds with vinyl ether in moderate yields. This method has been applied to the synthesis of 3,4-dihydro-2H-pyranochromens and 3,4-dihydro-2H-benzochromen. 3,4-Dihydro-2H-pyranochromens were easily converted to 4H-pyranochromens by elimination of ethoxy group. The structures of these compound were identified by IR and $^1H$ NMR-Spectra.