Highly Selective Synthesis of Dihydrobenzo[d]isoxazoles and Dihydrobenzo[d]oxazoles from Oximes and Arynes via in Situ Generation of Nitrones

An efficient method for the synthesis, of dihydrobenzo[d]isoxazoles and, dihydrobenzo[d]oxazoles bearing a quatenary carbon center has been, developed. The reaction involve generation of a ketonitrone intermediate in situ from, ketoxime and an aryne. A hovel thermal rearrangement of the dihydrobenzo[d]isoxazole products to the cortesponding dihydrobenzo [d] oxazoles has :been observed. These transformations tolerate a variety of functional groups and offer a rapid and efficient way to diverse dihydrobenzo[d]isoxazoles and dihydrobenzo[d]oxazoles under mild transition,mental-free conditions.