1.1: hexane / 48 h / 25 °C 2.1: Li; 4,4'-di-tert-butylbiphenyl / tetrahydrofuran / 0.5 h / -78 °C 2.2: phosphate buffer / tetrahydrofuran / -78 - 25 °C 2.3: 52 percent / PTSA / 12 h / 25 °C View Scheme

hydrogenchloride in dichloromethane T=0°C; 96 h;

triethylamine in ethanol 1 h; Heating;

triethylamine in ethanol 1 h; Heating;