3, 8-Thionanedione 1, 1-Dioxide. Synthesis and Solid-State Conformation

The title compound is conveniently prepared in 80% overall yield by ozonolysis at -78 °C of the cycloadduct of S02 with 1, 2-dimethylenecyclohexane. Single-crystal X-ray analysis establishes that the nine-membered ring adopts a twist-chair-chair conformation in which the sulfur atom and the midpoint of the C(5)-C(6) bond lie on a noncrystallographic C2 axis, but the ring shape differs significantly from that of cyclononane in order to accommodate transannular dipole-dipole interactions. Crystals are orthorhombic, space group P212121, with a = 8.963 (4) Å, b = 15.403 (7) Å, c = 6.724 (3) Å, and Z = 4. Atomic positional and thermal parameters were refined by full-matrix least-squares calculations to R = 0.032 over 913 statistically significant reflections. © 1979, American Chemical Society. All rights reserved.

Duke Scholars

Author Andrew T. McPhail Chemistry