trifluoroacetic acid in dichloromethane T=-78 - 20°C; Cyclization; 20 h; Product distribution; Further Variations:Reagents;

1: With trimethylsilyl trifluoromethanesulfonate in dichloromethane T=-78 - 20°C; 2: With hydrogenchloride in dichloromethane Further stages.;

titanium tetrachloride in dichloromethane T=-78 - 20°C;

1: trans-N-(4-(4-fluorophenyl)-6-isopropyl-5-(3-oxoprop-1-enyl)pyrimidin-2-yl)-N-methylmethanesulfonamide With lithium chloride; (S)-(-)-1,1'-bi-(2-naphthyloxy)(diisopropoxy)titanium in tetrahydrofuran T=20°C; 0.166667 h; 2: 1-ethoxy-1,3-bis-(trimethylsilanyloxy)-buta-1,3-diene With N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran T=20°C; 3: With phosphoric acid; trifluoroacetic acid more than 3 stages;

trimethylsilyl trifluoromethanesulfonate in dichloromethane T=0 - 20°C; Michael-retro-Michael-aldol reaction;

1: T=20°C; Cycloaddition; 1 h; 2: With triethylamine hydrofluoric acid in ethanol Aromatisation; desilylation; elimination;