1: 97 percent / hydrogen sulfide, triethylamine / ethanol / 5 °C / ice bath, overnight 2: 68 percent / methanol / 2 h / 66 °C / pH=9 3: 43 percent / tetrahydrofuran / 3 h / Heating View Scheme

1: 8 percent / NaOH / aq. ethanol / 20 h / Ambient temperature 2: 97 percent / hydrogen sulfide, triethylamine / ethanol / 5 °C / ice bath, overnight 3: 68 percent / methanol / 2 h / 66 °C / pH=9 4: 43 percent / tetrahydrofuran / 3 h / Heating View Scheme

in tetrahydrofuran 3 h; Heating;

1: 68 percent / methanol / 2 h / 66 °C / pH=9 2: 43 percent / tetrahydrofuran / 3 h / Heating View Scheme