IODIDE ASSISTED ZEOLITE CATALYZED 1,4-ADDITION OF WATER TO BUTADIENE MONOXIDE

Selective 1,4-addition of water to butadiene monoxide can be achieved in a liquid phase catalytic process using ultrastable Y zeolite as Bro nsted acid, potassium iodide, and an ether solvent. The reaction mecha nism could be elucidated based on the occurrence of intermediate react ion products. Iodide is added to the terminal unsaturated carbon atom of a protonated butadiene monoxide molecule. The strong solvent effect observed can be rationalised based on the nucleophilicity of the iodi de depending on the basicity of the ether function. With USY zeolite, the 2-butene-1,4-diol selectivity reaches 73.9% at 100% conversion whe n using 1,2-dimethoxyethane solvent, 2,5-dihydrofuran being the main b yproduct. With this catalytic system followed by an additional hydroge nation step, butadiene monoxide can be selectively converted into 1,4- butanediol. (C) 1998 Academic Press.