1: acetophenone With di-n-butylboryl trifluoromethanesulfonate; N-ethyl-N,N-diisopropylamine in dichloromethane T=-78°C; 0.5 h; 2: 2-butyn-1-al diethyl acetal in dichloromethane T=-78°C; 0.5 h;

1: With boron trifluoride diethyl etherate in dichloromethane 0.416667 h; Inert atmosphere; 2: With ammonium cerium (IV) nitrate; triethylamine in acetone Inert atmosphere;