The reaction of sodium with bis- and tris(alkoxy)benzenes in HMPA gives selectively the products of monodealkylation. The reaction proceeds through a dianion which fragments into an alkyl and an aryloxy anion. The positional selectivity of this fragmentation is governed by the structure of both the alkyl and aryloxy groups. With bis- and tris(alkoxy)benzenes which for symmetry reasons can afford aryloxy