Allylation of\nLactol in Water

We\ndeveloped a water-promoted cross-coupling of 3-hydroxyisobenzofuran-1(3<i>H</i>)-ones and allylic boronates under biocompatible conditions.\nThis approach facilitates the synthesis of diverse 3-allylic phthalides\nwith high yields and exceptional selectivity in a metal-free manner.\nThe versatility and practicality of this protocol underscore its significant\npotential for drug development and applications in medicinal chemistry.