Asymmetric Ortholithiation of Amides by Conformationally Mediated Chiral Memory: An Enantioselective Route to Naphtho- and Benzofuranones
作者:Jonathan Clayden、Christopher C. Stimson、Martine Keenan
DOI:10.1055/s-2005-871554
日期:——
An enantiomerically pure sulfinyl group ortho to an aromatic amide imposes absolute stereochemistry on the conformation of its Ar-CO axis. Sulfoxide-lithium exchange followed by addition to an aldehyde relays the chirality of the amide axis to the new hydroxyl-bearing stereogenic centre with good stereochemical fidelity. Lactonisation of the hydroxyamide gives naphthofuranones and benzofuranones, including the fungal metabolite isoochracein, but with substrate-dependent stereoselectivity.