Meaning of transannular

trans•an•nu•lar

Pronunciation: (trans-an'yu-lur, tranz-), [key]
— adj. Chem.
  1. of or pertaining to tautomerism in cyclic compounds that is characterized by the migration of an atom or group from one position in the ring to another.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.