Synthesis of hydroxybenzodioates aminophenols and diaryl selenides by [3+3] cyclizations of 1 3 bis(silyloxy) 1 3 butadienes with 3 silyloxy and 3 alkoxy 2 en 1 ones The regioselective cyclocondensation of 1 3 bis(trimethylsilyloxy) 1 3 butadienes with different substituted 3 silyloxy and 3 alkoxy 2 en 1 ones afforded 4 hydroxyisophthalates 3 hydroxyphthalates 2 hydroxyterephthalates 4 nitrophenols and diaryl selenides.