1: 90 percent / potassium hydroxide / methanol; H2O / 2 h / Heating 2: 98 percent / zinc / aq. NaOH / 2 h / 25 °C View Scheme

2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-75°C; 2 h;

1: 89 percent / sec-butyllithium / cyclohexane; tetrahydrofuran / -75 °C 2: 63 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h / -75 °C 3: 93 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

1: 89 percent / sec-butyllithium / cyclohexane; tetrahydrofuran / -75 °C 2: 63 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h / -75 °C 3: 93 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

1: 63 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h / -75 °C 2: 93 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

potassium hydroxide in methanol; water 2 h; Heating;

1.1: potassium carbonate; tributyltin hydride / 12 h / 60 °C 1.2: 74 percent / α,α'-azobis(isobutyronitrile) / benzene / 3 h / 60 °C 2.1: 91 percent / potassium hydroxide / ethanol; H2O / 2 h / 25 °C View Scheme

1: With tri-n-butyl-tin hydride; potassium carbonate T=60°C; 12 h; 2: With azobisisobutyronitrile in benzene T=60°C; 3 h;