1: diphenyl acetylene With titanium(IV) isopropylate; isopropylmagnesium chloride in diethyl ether T=-78 - -50°C; 2: 2-methoxyacetonitrile in diethyl ether T=-50°C; 3 h; 3: benzaldehyde in diethyl ether T=-50 - 20°C;

toluene-4-sulfonic acid in benzene 48 h; Ambient temperature;

toluene-4-sulfonic acid 48 h; Ambient temperature;