1: 86 percent / dibal / toluene / -78 - 0 °C 2: 90 percent / CHCl3 / Heating 3: 94 percent / dibal / toluene / -78 - 0 °C 4: 90 percent / TEA, DMAP / CH2Cl2 View Scheme

1: 86 percent / dibal / toluene / -78 - 0 °C 2: 86 percent / CHCl3 / Heating 3: 85 percent / dibal / toluene / -78 - 0 °C 4: 1.) KH / 1.) THF, DMF 5: 48percent aq. HF / acetonitrile / 0 °C 6: 80 percent / I2, Na2CO3 / acetonitrile / 3 h / 0 °C View Scheme

1: 86 percent / dibal / toluene / -78 - 0 °C 2: 90 percent / CHCl3 / Heating 3: 94 percent / dibal / toluene / -78 - 0 °C 4: 1.) KH / 1.) THF, DMF View Scheme

1: 86 percent / dibal / toluene / -78 - 0 °C 2: 86 percent / CHCl3 / Heating 3: 85 percent / dibal / toluene / -78 - 0 °C 4: 1.) KH / 1.) THF, DMF View Scheme

1: 86 percent / dibal / toluene / -78 - 0 °C 2: 90 percent / CHCl3 / Heating 3: 94 percent / dibal / toluene / -78 - 0 °C 4: 1.) KH / 1.) THF, DMF 5: 48percent aq.HF / acetonitrile / 0 °C View Scheme

1: 86 percent / dibal / toluene / -78 - 0 °C 2: 90 percent / CHCl3 / Heating 3: 94 percent / dibal / toluene / -78 - 0 °C 4: KH / 1.) THF, DMF View Scheme