Cycloetherification of dipeptide (L,L) N-Boc-(4-fluoro-3-nitro)Phe-Dopa methyl ester (11) gave exclusively the (m,p)-cyclophane (14) at the expense of the 15-membered (p,p)cyclophane (16). An efficient synthesis of cycloisodityrosine was consequently developed (C) 1998 Elsevier Science Ltd. All rights reserved.