10-Ethynyl-2,3,6,6a,9,10-hexa-hydro-1H-6,9-methano-pyrrolo[2,1-i][2,1]benzo-thia-zol-10-ol 5,5-dioxide.

In the title compound, C(13)H(15)NO(3)S, the sole classical hydrogen-bond donor is involved in an intra-molecular O-H⋯N hydrogen bond. In the crystal structure, pairs of mol-ecules related by inversion centres are linked by pairs of weak inter-molecular C-H⋯O inter-actions; these centrosymmetric pairs are, in turn, linked further by weak inter-molecular C-H⋯O inter-actions, forming two-dimensional sheets oriented parallel to (101).