Experimental and Computational Studies on the 1,3-Dipolar Cycloaddition between Enantiomerically Pure 2,3-Dihydrothiazoles and Nitrones

The diastereoselective 1,3-dipolar cycloaddition between nitrones and enantiomerically pure 2,3-dihydrothiazoles derived from L-cysteine, with different oxidation states at the sulfur atom has been studied experimentally and computationally. The reaction takes place with complete regioselectivity and diastereofacial selectivity. On the other hand, the exo/endo selectivity showed a clear dependence of the oxidation state at the sulfur atom. The computational calculations agree with the experimental findings.