Dihydropyranone Formation by <i>Ipso</i> C−H Activation in a Glucal 3-Carbamate-Derived Rhodium Acyl Nitrenoid

Abstract

By using (N-tosyloxy)-3-O-carbamoyl-D-glucal 10, which removes the need for a hypervalent iodine(III) oxidant, we provide evidence for rhodium nitrenoid-mediated ipso C-H activation as the origin of a C3-oxidized dihydropyranone product 3. This system may be especially susceptible to such a pathway because of the ease of forming a cation upon hydride transfer to the rhodium-complexed acyl nitrene.