N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile in tetrachloromethane T=20°C; 48 h; Reflux;

N-bromosuccinmide; dibenzoyl peroxide in tetrachloromethane 1.5 h; Irradiation;

1: 45 percent / LiAlH4 / diethyl ether / 3 h / 0 °C 2: 1.) lithium diisopropylamide / 1) THF, -78 deg C, 20 min; 2) THF, -78 deg C, 1 h 3: 73 percent / oxalyl chloride, DMSO / CH2Cl2 / 0.75 h / -78 °C 4: diethyl ether / 1 h / Ambient temperature 5: 95 percent / oxalyl chloride, DMSO / CH2Cl2 / 1 h / -78 °C 6: 1.) hexamethyldisilazane, n-BuLi / 1) THF, -78 deg C, 45 min; 2) THF, hexane, -78 deg C, 2 h 7: 48 percent / PTSA / toluene / Heating 8: 1.) tert-butyldimethylsilyl trifluoromethanesulfonate, pyridine / 1) CH2Cl2, 30 min; 2) CH2Cl2, , 2 h View Scheme