1: 81 percent / NaOH / aq. ethanol / r.t., 30min., then reflux, 4h 2: 1. polyphosphoric acid; 2. Se powder / 1. 190-200 degC, 1.5h; 2. 300 degC, 8h View Scheme

1: 81 percent / NaOH / aq. ethanol / r.t., 30min., then reflux, 4h 2: 1. polyphosphoric acid; 2. Se powder / 1. 190-200 degC, 1.5h; 2. 300 degC, 8h View Scheme

1: 95 percent / LiAlH4 / diethyl ether / 3 h / Heating 2: 81 percent / NaOH / aq. ethanol / r.t., 30min., then reflux, 4h 3: 1. polyphosphoric acid; 2. Se powder / 1. 190-200 degC, 1.5h; 2. 300 degC, 8h View Scheme

1: 1. conc. hydrochloric acid, NaNO2; / 1. 0 degC, 30min.; 2. 40 - 45 degC 2: 95 percent / LiAlH4 / diethyl ether / 3 h / Heating 3: 81 percent / NaOH / aq. ethanol / r.t., 30min., then reflux, 4h 4: 1. polyphosphoric acid; 2. Se powder / 1. 190-200 degC, 1.5h; 2. 300 degC, 8h View Scheme

1: Br2 / CHCl3 / Ambient temperature 2: 1) BuLi / 1) THF, Et2O, hexane, reflux, 1 h, 2) reflux, 1 h View Scheme

selenium; PPA 1. 190-200 degC, 1.5h; 2. 300 degC, 8h; Yield given. Multistep reaction. Yields of byproduct given;

n-butyllithium 1) THF, Et2O, hexane, reflux, 1 h, 2) reflux, 1 h; Yield given. Multistep reaction;