Didehydroisobenzofuran: A New Reactive Intermediate for Construction of Isoacenofuran.

An efficient generation method of didehydroisobenzofuran, a new heteroaryne species, was developed by bromine/lithium exchange of the dibromoisobenzofuran. The reactive intermediate, thus generated, was trapped by appropriate arynophile to give the [2+2], [2+3], and [2+4] cycloadducts, respectively. Moreover, the reaction could be applied to the syntheses of isoanthracenofurans (anthra[2,3‐c]furans), a new class of heteroacenes, with isoelectoronic structure to the corresponding acenoheteroles (anthra[2,3‐b]furans). An efficient generation method of didehydroisobenzofuran, a new heteroaryne species, was developed by bromine/lithium exchange of the dibromoisobenzofuran. The reactive intermediate, thus generated, was trapped by arynophiles to give various cycloadducts, one of which could be converted to isoanthracenofurans, a new class of heteroacenes, possessing unique physical properties (see scheme). [ABSTRACT FROM AUTHOR]