The synthesis of the requisite m-xylyl dibromides (Ia-Id) waa straightforward, is described in the Experimental Section, and requires no special comment, The conditions of the Wurtz reaction are relatively severe and the choice of substituents was made to determine what functional groups, if any, would survive these reaction conditions, permitting the isolation of useful quantities of substituted [2.2] metacyclophanes. In fact, the Wurtz dimerization of 3, ...
