1.1: 13 percent / AlCl3 / CH2Cl2 / 1 h / Heating 2.1: TMSI / CDCl3 / 30 h / 20 °C 2.2: MeOH 3.1: PTSA / benzene / 6 h / Heating View Scheme

toluene-4-sulfonic acid in benzene Cyclization; 6 h; Heating;

1.1: 13 percent / AlCl3 / CH2Cl2 / 1 h / Heating 2.1: TMSI / CDCl3 / 30 h / 20 °C 2.2: MeOH 3.1: PTSA / benzene / 6 h / Heating View Scheme

1.1: 97 percent / PPTS; water / acetone / 20 h / Heating 2.1: 13 percent / AlCl3 / CH2Cl2 / 1 h / Heating 3.1: TMSI / CDCl3 / 30 h / 20 °C 3.2: MeOH 4.1: PTSA / benzene / 6 h / Heating View Scheme

1: 100 percent / dioxane; H2O / 10 h / Heating 2: 73 percent / aq. KOH / methanol / 22 h / Heating 3: 63 percent / PPA / 1.5 h / 60 - 70 °C 4: 1.) NBS, dibenzoyl peroxide, 2.) H2O / 1.) CCl4, reflux, 4.5 h 5: 74 percent / PCC, Celite / CH2Cl2 / 3 h / 25 °C 6: 69 percent / AlCl3 / CH2Cl2 / 4 h / 55 °C 7: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 8: p-TsOH / benzene / 5 h / Heating View Scheme

1: 73 percent / aq. KOH / methanol / 22 h / Heating 2: 63 percent / PPA / 1.5 h / 60 - 70 °C 3: 1.) NBS, dibenzoyl peroxide, 2.) H2O / 1.) CCl4, reflux, 4.5 h 4: 74 percent / PCC, Celite / CH2Cl2 / 3 h / 25 °C 5: 69 percent / AlCl3 / CH2Cl2 / 4 h / 55 °C 6: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 7: p-TsOH / benzene / 5 h / Heating View Scheme

1: 1.) NBS, dibenzoyl peroxide, 2.) H2O / 1.) CCl4, reflux, 4.5 h 2: 74 percent / PCC, Celite / CH2Cl2 / 3 h / 25 °C 3: 69 percent / AlCl3 / CH2Cl2 / 4 h / 55 °C 4: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 5: p-TsOH / benzene / 5 h / Heating View Scheme

1: 63 percent / PPA / 1.5 h / 60 - 70 °C 2: 1.) NBS, dibenzoyl peroxide, 2.) H2O / 1.) CCl4, reflux, 4.5 h 3: 74 percent / PCC, Celite / CH2Cl2 / 3 h / 25 °C 4: 69 percent / AlCl3 / CH2Cl2 / 4 h / 55 °C 5: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 6: p-TsOH / benzene / 5 h / Heating View Scheme

1: 74 percent / PCC, Celite / CH2Cl2 / 3 h / 25 °C 2: 69 percent / AlCl3 / CH2Cl2 / 4 h / 55 °C 3: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 4: p-TsOH / benzene / 5 h / Heating View Scheme

1: 1.) Me3SiI, 2.) MeOH / 1.) CDCl3, 25 deg C, 27 h 2: p-TsOH / benzene / 5 h / Heating View Scheme