1: With dimethylsulfide borane complex in tetrahydrofuran; toluene T=0 - 65°C; 5.5 h; Inert atmosphere; 2: With hydrogenchloride in tetrahydrofuran; water; toluene 2 h; Reflux; 3: With sodium hydroxide in tetrahydrofuran; water; toluene

potassium carbonate in N,N-dimethyl-formamide 6 h; Ambient temperature;