Total Synthesis of Ervaoffine J and K

Herein, we describe the total synthesis of ervaoffine J & K from a central intermediate. Ervaoffine J was synthesized in eight steps in 14 % yield. Our strategy features an aerobic Winterfeldt oxidation to introduce the 4-quinolone moiety. Ervaoffine K was produced in ten steps and 10 % yield. The synthesis leveraged (bromodifluoromethyl)-trimethylsilane to induce a regioselective von Braun-type C-N bond fragmentation. This C-N bond cleavage unveiled the tetrasubstituted all-syn cyclohexane core of ervaoffine K and enabled the completion of its synthesis. The unified total syntheses of ervaoffine J and ervaoffine K were achieved from a common intermediate. The synthesis of ervaoffine J featured an aerobic, Winterfeldt oxidation and proceeded in 8 steps and 14 % overall yield. A von Braun-like C-N bond cleavage enabled access to ervaoffine K in 10 steps and 10 % yield.image