A new approach to 4,6-disubstituted-3,4-dihydropyran-2-ones by Domino Michael addition-cyclization reaction under PTC conditions
作者:Nicoletta Gaggero、Domenico C.M. Albanese、Donatella Nava
DOI:10.1016/j.tet.2014.09.022
日期:2014.11
Domino Michael addition-cyclization reactions of α,β-unsaturatedcarbonylcompounds with activated 1,3-dithiane-2-carbothioate esters under solid-liquid phase transfer catalysis conditions provide 4,6-disubstituted-3,4-dihydropyran-2-one-3,3-dithioacetals in good chemical yield. Desulfurization proceeds chemoselectively under mild conditions affording 3,4-dihydropyran-2-ones in high yields.
The chemistry of α,β-ditosyloxyketones: new and convenient route for the synthesis of 1,4,5-trisubstituted pyrazoles from α,β-chalcone ditosylates
作者:Om Prakash、Deepak Sharma、Raj Kamal、Rajesh Kumar、Reshmi R. Nair
DOI:10.1016/j.tet.2009.10.001
日期:2009.12
reagents such as phenylhydrazine hydrochloride, semicarbazide hydrochloride and thiosemicarbazide in suitable conditions leads to 1,2-aryl shift, thereby providing a novel route for the synthesis of 1,4,5-trisubstitutedpyrazoles.