toluene-4-sulfonic acid in tetrahydrofuran; water; isopropyl alcohol 1 h; Heating;

1: 96 percent / p-TsOH / tetrahydrofuran; H2O; propan-2-ol / 1 h / Heating 2: 1) sodium hexamethyldisilazide / 1) THF, toluene, 25 deg C, 2 h, 2) THF, a) -100 deg C, 30 min, b) to 25 deg C, 3 h 3: p-TsOH / tetrahydrofuran; H2O / 0.08 h / Heating 4: 1) sodium hexamethyldisilazide / 1) THF, toluene, 1 h,k 20 deg C, 2) -100 to 0 deg C, 4 h 5: 90 percent / Li, NH3, t-BuOH / tetrahydrofuran / -40 °C 6: p-TsOH / tetrahydrofuran; H2O / 0.17 h / Heating 7: 1-methylcyclohex-1-ene, NaClO2, H2NSO3H / CH2Cl2; H2O / 1) 0 deg C, 15 min, 2) to 25 deg C, 30 min 8: 68 percent / Ph3P, diethyl azodicarboxylate / tetrahydrofuran / 1 h View Scheme