Unexpected Formation of 10-Iodo- and 10-Chlorocamphor under Halosulfonylation Conditions, and Convenient Routes to 10-Chloro- and 10-Bromocamphor

The generation of camphor-10-sulfonyl iodide in situ under halosulfonylation conditions or exposure of camphor-10-sulfonyl chloride to copper(II) chloride under Asscher–Vofsi conditions leads unexpectedly to the formation of 10-iodocamphor or 10-chlorocamphor, respectively. Additionally, convenient syntheses of 10-bromocamphor and 10-chlorocamphor have been achieved by extension of a previously reported methodology.