The Claisen rearrangement of 1,4-bis(m-methoxyphenoxy-)2-butyne (1b) gives four isomeric dimethoxy-6H-benzofuro[3,2-c]-6a,11a-dihydro-11a-methylbenzopyrans (3), three dimethoxy-4b,9b-dihydro-4b,9b-dimethylbenzofuro[3,2-b]benzofurans (4), and, in the presence of acid, three dimethoxy-5a,10b-dihydro-5a,10b-dimethylbenzofuro[2,3-b]benzofurans (5), which have been separated and identified by proton and13C nmr spectroscopy. Based on the isolation of two chromene intermediates and their conversion to3and4, as well as the isomerization of3to4and4to5, a "double Claisen" mechanism is proposed. The reaction is not regiospecific but the two [3,3] sigmatropic shifts occur preferentially to theparapositions of the methoxy substituents.