2,3-dicyano-5,6-dichloro-p-benzoquinone in diethyl ether Ambient temperature;

1: 2,4-dihydroxy-3-(3-methylbut-2-en-1-yl)benzaldehyde With selenium bromide polystyrene resin in dichloromethane T=0 - 25°C; Solid phase reaction; 0.5 h; 2: methyl (triphenylphosphoranylidene)acetate With N,N-diethylaniline T=165°C; Solid phase reaction; 3 h; 3: With dihydrogen peroxide in tetrahydrofuran T=25°C; Oxidation; elimination; 0.5 h;

Multistep reaction.;