Stereoselective synthesis of (3R)-3-alkyl-4,1-benzoxazepine-2,5-diones.

Novel 3-alkyl-4,1-benzoxazepine-2,5-diones were synthesized in good ee exploiting the chiral pool methodology, an economical way of asymmetric synthesis. Various anthranilic acids are coupled with different α-haloacids to afford N-acylated anthranilic acid intermediates which undergo cyclization to (3R)-3-alkyl-4,1-benzoxazepines-2,5-diones.