Carbamoyl Functionalized Bent para-Phenylenes via an Unexpected Reaction of the Burgess Reagent with α-Ketols.

The attempted dehydration of macrocyclic α-ketols with the Burgess reagent has resulted in the unexpected synthesis of carbamoylated, bent para-phenylene units. The same reaction with an acyclic analogue affords the intended dehydration product, indicating that the change in reactivity is conformationally controlled and a result of the bifunctional nature of the Burgess reagent.