Catalytic asymmetric synthesis of the docetaxel (Taxotere) side chain: organocatalytic highly enantioselective synthesis of esterification-ready α-hydroxy-β-amino acids

A highly enantioselective catalytic route to protected β-amino-α-hydroxy acids, such as the side chain of Taxotere, is presented. The organocatalytic asymmetric reactions between unmodified protected α-oxyaldehydes and N-Boc-protected aryl imines give the corresponding compound with up to >19:1 dr and 99-99% ee.