tris(pentafluorophenyl)-borane T=20°C; 0.166667 h;

zinc in N,N-dimethyl-formamide T=60°C; 7 h; Inert atmosphere;

1: hex-5-ynoic acid With oxalyl dichloride in dichloromethane 2.5 h; Inert atmosphere; 2: With indium(III) chloride in dichloromethane 3 h; Inert atmosphere; 3: allyl alcohol in dichloromethane Inert atmosphere;

toluene-4-sulfonic acid in benzene