potassium dihydrogenphosphate; NaClO2 in water; dimethyl sulfoxide

1: furolt;3,2-cgt;pyridine With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: carbon dioxide in tetrahydrofuran; hexane T=-78 - 20°C; 3 h;

1: 65 percent / p-toluenesulfonic acid, acetic anhydride / 5 h / Heating 2: 91 percent / KOH / aq. ethanol / 2 h / Heating View Scheme

2: 95 percent / hydroxylamine hydrochloride, K2CO3 / aq. ethanol / 2 h / Ambient temperature 3: 65 percent / p-toluenesulfonic acid, acetic anhydride / 5 h / Heating 4: 91 percent / KOH / aq. ethanol / 2 h / Heating View Scheme