1: Methyltriphenylphosphonium bromide With n-butyllithium in tetrahydrofuran T=0°C; 0.25 h; Inert atmosphere; 2: 2-Hydroxy-3-methyl-benzaldehyde in tetrahydrofuran T=0 - 20°C; Inert atmosphere;

1: triphenyl-methyl-phosphonium iodide With n-butyllithium in tetrahydrofuran; hexane T=0°C; 2 h; 2: 2-Hydroxy-3-methyl-benzaldehyde in tetrahydrofuran; hexane T=-78°C; Wittig reaction;

tributyl-amine; tin(IV) chloride in 1,2-dichloro-ethane Heating;

1: 75 percent / K2CO3 / dimethylformamide 2: 81 percent / Grubbs second-generation catalyst / CH2Cl2 / 20 °C View Scheme