A Possible Mechanism for Furan Formation in the Tropospheric Oxidation of Dienes

摘要

The isoprene + OH gas-phase reaction has been widely studied because of its relevance in tropospheric chemistry.However,an unsolved question remains concerning the mechanism for the formation of the observed 3-methylfuran.OH addition to dienes,such as isoprene and butadiene,is assumed to occur only at the external carbon atoms,thus restricting furan formation to a step after addition at C_1 and C_4.Moreover,cyclization of the carbon chain necessarily involves a cis conformation.In this work,several quantum chemistry methods have been used to model five different reaction paths for furan formation.A mechanism that is highly favored for intermediates that do not undergo collisional stabilization has been identified.