Concise Synthesis of 4-Acylamino Analogues of 2-Aminobicyclo[3.1.0]hexane-2,6-dicarboxylic Acids (LY354740) from an Acylnitroso Diels−Alder Cycloadduct

Concise total syntheses of 4-acylamino analogues of LY354740 were accomplished employing an N-Boc acylnitroso Diels-Alder cycloadduct as the starting material. The syntheses involved N-O bond cleavage, oxidation, intermolecular cyclopropanation, Bucherer-Bergs reaction, hydrolysis, and regioselective acylation with a temporary copper chelate. The synthesis of an optically active compound was also achieved.