Rings of five and six: Donor alkenyl rhodiumcarbenoidsgeneratedfrom 3,3‐dimethylcyclopropenylcarbinols exhibit high reactivity in intramolecular CHinsertions. The reactions proceed under remarkably mild conditions, tolerate the presence of the free hydroxy group, and afford an efficient and stereoselective access to a variety of functionalized carbocycles and oxygen heterocycles.