A controversy about the structures of five-membered ring sultones obta
ined by treatment of camphenes with acetic and concentrated sulfuric a
cids has been resolved by X-ray analysis of the sultone obtained from
racemic camphene, namely, endo-3H-10, -dimethyl-4-oxa-5-thiatricyclo[5
.2.1.0(3,7)]decane S,S-dioxide, (also known as 10-bornanesulfonic acid
2-hydroxy-gamma-sultone), C10H16O3S Five-membered saturated sultone r
ings are shown to be conformationally flexible.