1.1: Mg; iodine 1.2: 81 percent / tetrahydrofuran / 8 h 2.1: 82 percent / pyridinium chlorochromate; NaOAc; molecular sieves 4 Angstroem / CH2Cl2 / 0.75 h / 20 °C View Scheme

molecular sieve; pyridinium chlorochromate 1.) THF, 8 h; 2.) CH2Cl2, 40 min; Yield given. Multistep reaction;