6-endo or not 6-endo, that is the question: correcting an erroneous structural assignment and mechanistic presumption

Abstract

Careful reading of a published article uncovered a specious structural assignment, which has so far remained unchallenged. An alternate structure has been suggested and the experimental procedure repeated. Subsequently, a more rigorous analytical characterization confirmed the true structure to be a cyclic dimer of the structure proposed in the original paper, thereby negating their singular claim of an otherwise unobserved type of 6-endo cyclization.