Synthesis of beta -amino-alpha -hydroxy esters and beta -amino-alpha -azido ester by Sharpless asymmetric aminohydroxylation, byproducts analysis

Synthesis of enantiomerically pure beta -amino-alpha -hydroxy esters, e.g., I, and beta -amino-alpha -azido ester using Sharpless AA as a key step is described. A side reaction, the oxidn. of the beta -hydroxy-alpha -amino ester into the alpha ,alpha -di-tert-butyloxycarbamoyl-beta -ketoester under AA conditions, is also documented. [on SciFinder (R)]