1.1: acetic acid / 0.5 h / 23 - 100 °C 2.1: tetrahydrofuran / 12 h / 20 - 23 °C 3.1: dichloromethane / 2 h / -30 °C 3.2: 2 h / -30 - 20 °C 4.1: dichloromethane / 2 h / 23 - 60 °C View Scheme

1: palladium/charcoal; concentrated aqueous HCl / Hydrogenation 2: aqueous H3aso4; concentrated H2SO4 View Scheme

1: H2 / 5percent Pd/C / methanol 2: 1.) 42percent HBF4, isoamyl nitrite / 1.) MeOH, 0 deg C, 4 h, 2.) xylene, reflux, 5 h View Scheme