borane in tetrahydrofuran T=0°C; 5 h;

hydrogen; palladium on activated charcoal in ethanol P=2844.3 Torr;

1: With benzo[1,3,2]dioxaborole; rhodium complex 2 in toluene T=20°C; Addition; Hydroboration; 2 h; 2: With sodium hydroxide; water; dihydrogen peroxide in toluene T=20°C; Oxidation; 2 h; Title compound not separated from byproducts;

1: (i) HCl, (ii) H2S 2: Irradiation View Scheme

1: 71.3 percent / pyridine / 1 h / 0 - 2 °C 2: 93.7 percent / dimethylsulfoxide / 1) 93 deg C, 1.5h, 2) 100 deg C, 1h 3: 43.3 percent / conc. H2SO4, H2O / 0.5 h / Heating View Scheme