Mechanism for the gas-phase reaction between NO3 and furan: A theoretical study

The furan-ONO2 intermediate (IN1) is formed via a barrierless association. The most favorable two paths are IN1 → 3H-furan-2-one via a simultaneous 1,2-H shift and the loss of NO2 and IN1 → cis-butenedial via a simultaneous loss of NO2 and ring opening.