A synthesis of (L, L)-N, N-dimethylcycloisodityrosine 4 based on intramolecular SNAr reaction is reported. A possible explanation was proposed to account for the facile epimerization encountered in the cycloetherification of dipeptide (L,L)-10 and a solution to this problem led to a formal total synthesis of deoxybouvardin. (C) 1997 Elsevier Science Ltd.