Base-promoted annulation of α-hydroxy ketones and dimethyl but-2-ynedioate: straightforward access to pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones
A novel and efficientcascadeannulation of tertiary α-hydroxy ketones and dimethyl but-2-ynedioate is reported. The reaction, which only requires a base as the promoter, provides a straightforward access to polysubstituted pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones under very mild reactionconditions.
新型和有效的级联环的叔α-羟基酮和2-丁炔基二甲基二甲酸酯。该反应只需要一个碱作为促进剂,就可以直接获得多取代的吡喃并[4,3- a ]喹诺嗪-1,4,6 (2 H)-三酮和2 H-吡喃-2,5(6)H)-二酮在非常温和的反应条件下。
Copper-Catalyzed [4 + 1] Annulation between α-Hydroxy Ketones and Nitriles: An Approach to Highly Substituted 3(2<i>H</i>)-Furanones
A copper-catalyzed [4 + 1] annulation between α-hydroxy ketones and nitriles has been developed. The reaction provides a facile and efficient method for the construction of a wide range of highlysubstituted 3(2H)-furanones, a class of important compounds known to be associated with several biological activities.
A carbon dioxide-promoted and silver acetate-catalyzed hydration of propargylicalcohols for the efficient synthesis of tertiary α-hydroxy ketones has been developed. The reaction is proposed to proceed via a tandem process of carbon dioxide incorporation into propargylicalcohols and subsequent hydrolysis.