2,3-Dihydro-4<i>H</i>-pyran-4-ones and 2,3-Dihydro-4-pyridinones by Cyclizations of α,β-Unsaturated 1,3-Diketones
作者:Franklyn K. MacDonald、D. Jean Burnell
DOI:10.1021/jo901355e
日期:2009.9.18
β-unsaturated 1,3-diketones cyclize to 2,3-dihydro-4H-pyran-4-ones in an acidic aqueous medium, with exceptions being α,β-unsaturated 1,3-diketones in which the β carbon is substituted by a phenyl group. Addition of 1-butanamine to the reaction medium results in the formation of 2,3-dihydro-4-pyridinones, which appear to arise via an initial 1,4-addition of the amine to the α,β-unsaturated 1,3-diketones.
在酸性水性介质中,多种α,β-不饱和1,3-二酮环化为2,3-二氢-4 H -pyran-4-one,但α,β-不饱和1,3-二酮除外β碳被苯基取代。将1-丁胺添加到反应介质中会导致形成2,3-二氢-4-吡啶酮,这似乎是由于将胺最初添加到α,β-不饱和的1,3-中而发生的,即最初的1,4-添加。二酮。