1: With sodium tetrahydroborate; acetic acid in dichloromethane T=20°C; 1 h; Inert atmosphere; 2: With phenyl silane; triethylamine in tetrahydrofuran T=20°C; 2 h; Inert atmosphere;

pyridinium chlorochromate in dichloromethane

1: 89 percent / Et2Zn / hexane; 1,2-dichloro-ethane / 16 h / 20 °C 2: pyridinium chlorochromate / CH2Cl2 View Scheme