1: 64 percent / PPh3; DEAD / diethyl ether / 3 h / 20 °C 2: 92 percent / CH2Cl2; pyridine / 3 h / 0 °C View Scheme

1: 64 percent / PPh3; DEAD / diethyl ether / 3 h / 20 °C 2: 92 percent / CH2Cl2; pyridine / 3 h / 0 °C 3: 93 percent / LiCl; Et3N; PdCl2(PPh3)2 / dimethylformamide / 20 h / 90 °C / 41254.1 Torr View Scheme

triphenylphosphine; diethylazodicarboxylate in diethyl ether T=20°C; Esterification; Mitsunobu reaction; 3 h;