Diastereoselective syntheses of 3-aryl-5-(arylalkyl)-6-methyl-1-(1-phenylethyl)thioxotetrahydropyrimidin-4(1H)-ones: A stereochemical perspective from endo and exocyclic chiral centres
Aldol reactions of 2-thioxotetrahydropyrimidin-4(1H)-ones: stereoregulations from endo- and exocyclic chiral centres
作者:Varun Kumar、Kapil Kumar、Anang Pal、Gopal Lal Khatik、Vipin A. Nair
DOI:10.1016/j.tet.2012.12.020
日期:2013.2
reactions of conformationally restricted 3-aryl-1-((S)-1-phenylethyl)-2-thioxotetrahydropyrimidin-4(1H)-ones governed the formation of anti aldol adducts, by a kinetic reaction pathway. The preferential formation of the anti aldol diastereomers was also assisted by the steric effects of the electrophile through diastereofacial selection while the electroniceffects of the arylgroup at N3 remained subtle.
Diastereoselective syntheses of 3-aryl-5-(arylalkyl)-6-methyl-1-(1-phenylethyl)thioxotetrahydropyrimidin-4(1H)-ones: A stereochemical perspective from endo and exocyclic chiral centres
作者:Varun Kumar、Pallepogu Raghavaiah、Shaikh M. Mobin、Vipin A. Nair
DOI:10.1039/c0ob00230e
日期:——
Diastereoselective syntheses of 3-aryl-(S/R)-6-methyl-1-[(S/R)-1-phenylethyl)]-2-thioxotetrahydro pyrimidin-4(1H)-ones were achieved in good yields by the condensation of aryl isothiocyanates with ethyl 3-(1-phenylethylamino)butanoate in a one-pot reaction. Benzylation of these substrates illustrated that the orientations of the exocylic and endocylic groups determine the stereochemical outcome of the product formed.