1: 4-THP-CH2PPh3I With lithium hexamethyldisilazane in tetrahydrofuran T=-5 - 15°C; 2.5 h; 2: ethyl (4-cyclopropylsulfonylphenyl)oxoacetate in tetrahydrofuran T=0 - 25°C; 17 h; 3: With hydrogenchloride; methanol; sodium hydroxide; water more than 3 stages;

1: 4-THP-CH2PPh3I With lithium hexamethyldisilazane in tetrahydrofuran T=0 - 20°C; Wittig olefination; 3 h; Large scale reaction; 2: ethyl 2-(4-(cyclopropylthio)phenyl)-2-oxoacetate in tetrahydrofuran T=0 - 20°C; Wittig olefination; Large scale reaction; Further stages;