1: 86 percent / imidazole / dimethylformamide / 2 h / Ambient temperature 2: 1.) lead tetraacetate, 2.) Red-Al / 1.) benzene, pyridine, 25 deg C, 10 min, 2.) water, 1,5h 3: 91 percent / N-chlorosuccinimide, dimethyl sulfide / 1.) CH2Cl2, -20 deg C, 30 min, 2.) 0 deg C, 30 min 4: 1.) n-butyllithium, 2.) 5percent H2O2 / 1.) hexane, THF,-50 deg C, 15 min, 2.) chloroform, 1 min View Scheme

1: 86 percent / imidazole / dimethylformamide / 2 h / Ambient temperature 2: 1.) lead tetraacetate, 2.) Red-Al / 1.) benzene, pyridine, 25 deg C, 10 min, 2.) water, 1,5h 3: 91 percent / N-chlorosuccinimide, dimethyl sulfide / 1.) CH2Cl2, -20 deg C, 30 min, 2.) 0 deg C, 30 min View Scheme