Stereospecific synthesis of 2,2,3-trisubstituted tetrahydroquinolines: application to the total syntheses of benzastatin E and natural virantmycin

An efficient methodology for the synthesis of 2,2,3-trisubstituted tetrahydroquinolines has been developed, which involves the triphenylphosphine–CCl4-mediated stereospecific rearrangement of α,α-disubstituted indoline-2-methanols to 2,2,3-trisubstituted tetrahydroquinolines . The rearrangement precursors are readily prepared by the diastereoselective Grignard addition to 2-acylindolines . The total syntheses of (+)-benzastatin E () and natural virantmycin () were accomplished utilizing this methodology. This rearrangement reaction might afford some chemical precedent for the biogenetic pathway of the benzastatin family.