hydrogenchloride T=95°C; 24 h;

pyridine; copper(I) oxide 2 h; Heating;

1: 97 percent / K2CO3 / acetone / 5 h / Heating 2: 93 percent / NaOMe / 5 h / Heating 3: 1) I2, KI, 20percent aq. NH4OH / 1) water, dioxane, 1 h, ice-water bath, 2) diphenyl ether, 4 h, 195 deg C 4: 89 percent / BBr3 / CH2Cl2 / 1) -22 deg C, 2 h, 2) r.t., 36 h 5: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 6: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 93 percent / NaOMe / 5 h / Heating 2: 1) I2, KI, 20percent aq. NH4OH / 1) water, dioxane, 1 h, ice-water bath, 2) diphenyl ether, 4 h, 195 deg C 3: 89 percent / BBr3 / CH2Cl2 / 1) -22 deg C, 2 h, 2) r.t., 36 h 4: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 5: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 1) I2, KI, 20percent aq. NH4OH / 1) water, dioxane, 1 h, ice-water bath, 2) diphenyl ether, 4 h, 195 deg C 2: 89 percent / BBr3 / CH2Cl2 / 1) -22 deg C, 2 h, 2) r.t., 36 h 3: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 4: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

2: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 3: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 89 percent / BBr3 / CH2Cl2 / 1) -22 deg C, 2 h, 2) r.t., 36 h 2: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 3: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 80 percent / diphenyl ether / 4 h / 195 °C 2: 89 percent / BBr3 / CH2Cl2 / 1) -22 deg C, 2 h, 2) r.t., 36 h 3: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 4: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 97 percent / Cu2O, pyridine / 2 h / Heating; other alkynes, also with 8-iodoumbelliferone 2: 48 percent / conc. HCl / 24 h / 95 °C View Scheme

1: 1.) NH2OH*HCl, CuSO4*5H2O, conc. NH4OH / 1.) H2O, EtOH, 30 min; 2.) pyridine, reflux, overnight 2: 197 mg / (Ph3P)3RhCl / acetonitrile; H2O / 7 h / Heating 3: 25 mg / acetic anhydride / 6 h / Heating View Scheme