1: cyclopropyl phenyl sulphide With n-butyllithium in tetrahydrofuran; hexane T=0°C; 1 h; 2: α-(benzyloxymethyl)cyclohexanone in tetrahydrofuran; hexane T=-78 - 0°C; 1.5 h; 3: With water in tetrahydrofuran; hexane

toluene-4-sulfonic acid in water; toluene T=90°C; 5 h;