1.1: n-BuLi; DMPU / tetrahydrofuran; hexane / 0.25 h / 25 °C 1.2: 85 percent / triethylamine / tetrahydrofuran / 0 °C 2.1: n-BuLi / tetrahydrofuran; hexane / -78 °C 2.2: 89 percent / n-BuLi / tetrahydrofuran; hexane / 0.08 h / -78 °C 3.1: potassium tert-butoxide / tetrahydrofuran / 25 °C 3.2: aq. HF / acetonitrile / 1 h / 25 °C 4.1: 42 percent / t-BuOK / 2-methyl-propan-2-ol; tetrahydrofuran / 0.25 h / 25 °C View Scheme

1: NEt3 / tetrahydrofuran / 0 °C 2: 1) BuLi / 1) THF, -78 deg C, 2) HOAc, THF, -78 deg C 3: 1) BuLi / 1) THF, -78 deg C, 2) -78 deg C to RT 4: 1) t-BuOK, 2) HF / 1) THF, RT, 2) CH3CN, RT 5: t-BuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 0.25 h / 25 °C View Scheme

1: 1) BuLi / 1) THF, -78 deg C, 2) HOAc, THF, -78 deg C 2: 1) BuLi / 1) THF, -78 deg C, 2) -78 deg C to RT 3: 1) t-BuOK, 2) HF / 1) THF, RT, 2) CH3CN, RT 4: t-BuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 0.25 h / 25 °C View Scheme

1: 53 percent / m-chloroperbenzoic acid / CCl4 / 24 h / Heating 2: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 3: tetrahydrofuran / -78 - (-50) deg C, 1 h; rt, 30 min View Scheme

sodium hydroxide; methyl iodide Multistep reaction;

1: 1.) n-Butyllithium / 1.) THF, hexane, -78 deg C, 15 min, 2.) -78 deg C, 15 min 2: 1.) Methyl iodide, 2.) NaOH View Scheme

in tetrahydrofuran -78 - (-50) deg C, 1 h; rt, 30 min; Yield given;

lithium hexamethyldisilazane 1.) THF, hexane, -78 deg C, 1 h; -78 deg C to room temperature, 1.5 h, 2.) -78 deg C to room temperature, 3.) H2O; Yield given. Multistep reaction;

(i) MeLi*LiBr, (ii) /BRN= 969135/; Multistep reaction;