toluene-4-sulfonic acid in tetrahydrofuran; water; isopropyl alcohol 0.5 h; Heating;

1: 97 percent / p-TsOH / tetrahydrofuran; H2O; propan-2-ol / 0.5 h / Heating 2: 1) sodium hexamethyldisilazide / 1) THF, toluene, 25 deg C, 2 h, 2) THF, a) -100 deg C, 30 min, 2) to 25 deg C, 3 h 3: p-TsOH / tetrahydrofuran; H2O / 0.08 h / Heating 4: 1-Methylcyclohex-1-ene, NaClO2, H2NSO3H / CH2Cl2; H2O / 1) 0 deg C, 15 min, 2) to 25 deg C, 30 min View Scheme

1: 97 percent / p-TsOH / tetrahydrofuran; H2O; propan-2-ol / 0.5 h / Heating 2: 1) sodium hexamethyldisilazide / 1) THF, toluene, 25 deg C, 2 h, 2) THF, a) -100 deg C, 30 min, 2) to 25 deg C, 3 h 3: p-TsOH / tetrahydrofuran; H2O / 0.08 h / Heating 4: 1-Methylcyclohex-1-ene, NaClO2, H2NSO3H / CH2Cl2; H2O / 1) 0 deg C, 15 min, 2) to 25 deg C, 30 min 5: 72 percent / Ph3P, diethyl azodicarboxylate / toluene View Scheme