Author/Authors :
Cainelli، نويسنده , , Gianfranco and Galletti، نويسنده , , Paola and Giacomini، نويسنده , , Daria and Quintavalla، نويسنده , , Arianna، نويسنده ,
Abstract :
The endo/exo stereoselectivity of the Diels–Alder cycloaddition between cyclopentadiene and 3-crotonoyl-2-oxazolidinone catalysed by Et2AlCl is temperature- and solvent-dependent. Eyring plots of ln(endo/exo) versus 1/T show different inversion temperatures (Tinv) depending on the reaction solvent. Using toluene-d8 we found a break temperature (TNMR) in a variable temperature 13C NMR experiment of the starting oxazolidinone, and this TNMR corresponded to the Tinv. In several cases the differential activation entropy manages the observed stereoselectivity.
