5-(1H-Inden-2-yl)-1,3-benzodioxole.

In the title compound, C(16)H(12)O(2), the non-H atoms are coplanar with a mean r.m.s. deviation of 0.0260 (2) Å. The deviations of the bond angles from normal values at the indenyl junction C atom and the indenyl bridgehead C atom nearest the junction are imposed by the five-membered ring geometry. Due to conjugation, the single bond linking the two ring systems [1.455 (3) Å] is significantly shorter than the formal single bonds in the five-membered carbocyclic ring [1.500 (3) and 1.489 (3) Å].