1: CrO3, Ac2O / acetic acid 2: NaBH4, CeCl3 / methanol 3: mercuric chloride, samarium / tetrahydrofuran / 2 h / Ambient temperature 4: 58 percent / molecular sieve 5 Angstroem, PCC / CH2Cl2 / 24 h / Ambient temperature View Scheme

1: NaBH4, CeCl3 / methanol 2: mercuric chloride, samarium / tetrahydrofuran / 2 h / Ambient temperature 3: 58 percent / molecular sieve 5 Angstroem, PCC / CH2Cl2 / 24 h / Ambient temperature View Scheme

1: mercuric chloride, samarium / tetrahydrofuran / 2 h / Ambient temperature 2: 58 percent / molecular sieve 5 Angstroem, PCC / CH2Cl2 / 24 h / Ambient temperature View Scheme

in dimethyl sulfoxide

lithium perchlorate; triethylamine in acetonitrile 3 h; Irradiation;