1: With potassium tert-butylate in tetrahydrofuran; methanol; acetone T=-5 - 25°C; 1.5 h; 2: With hydrogenchloride in tetrahydrofuran; methanol; acetone pH=7;

1: With sodium hydroxide in water T=20 - 50°C; 1.5 h; 2: With hydrogenchloride in water T=-5 - 0°C; pH=1.5; 1 h;