General method for asymmetric synthesis of alpha-methylsulfinyl ketones: application to the synthesis of optically pure oxisuran and bioisosteres

The first asymmetric synthesis of oxisuran and various related bioisosteres in optically pure form, where the pyridine ring has been replaced by another aromatic ring, is described. The synthesis of the sulfoxides proceeded using DAG methodology, a powerful approach for the synthesis of dialkyl chiral sulfoxides. Epimerization at sulfur was circumvented with the use of N,N-dimethylhydrazones, resulting in the complete inversion of chirality.