triphenylphosphine in dichloromethane

1: 76 percent / PBr3, pyridine / diethyl ether / 1) -20 to 25 deg C, 2h, 2) 20 min, reflux 2: 1) LDA / 1) THF, HMPT, -80 deg C, 10-15 min, 2) THF, -80 to 0 deg C, 4h 3: 82 percent / DIBAL / diethyl ether; hexane / 1) -80 deg C, 3h, 2) -80 to -20 deg C 4: 86 percent / PPh3 / CH2Cl2 / 0.58 h / 0 °C View Scheme

1: 1) LDA / 1) THF, HMPT, -80 deg C, 10-15 min, 2) THF, -80 to 0 deg C, 4h 2: 82 percent / DIBAL / diethyl ether; hexane / 1) -80 deg C, 3h, 2) -80 to -20 deg C 3: 86 percent / PPh3 / CH2Cl2 / 0.58 h / 0 °C View Scheme

1: 82 percent / DIBAL / diethyl ether; hexane / 1) -80 deg C, 3h, 2) -80 to -20 deg C 2: 86 percent / PPh3 / CH2Cl2 / 0.58 h / 0 °C View Scheme