Chiral linker. Part 3: Synthesis and evaluation of aryl substituted m-hydrobenzoins as solid supported open chain chiral auxiliaries for the diastereoselective reduction of α-keto esters

Five partly novel aryl substituted m-hydrobenzoins were synthesized and the corresponding desymmetrized hydrobenzoin ethers evaluated as open chain chiral auxiliaries in the L-Selectride® mediated stereoselective reduction of phenylglyoxylates, resulting in de values of up to 91%. Two optimized auxiliary structures were immobilized on commercially available Wang-resin and applied as a reusable solid supported chiral auxiliary in the same type of reaction.