Rapid formation of β-allyl substituted isotetronic acid derivatives via Claisen rearrangement using a microfludic device

The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150 °C and a flow rate of 1 mL/h. The strategy provides an efficient alternative way to β-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.