HD exchange of 1-methylcycloalkenes in dilute acid at elevated temperatures

Specifically deuteriated cycloalkenes 1-trideuteriomethylcyclopentene-2,5,5-d 6 (1b), 1-trideuteriomethylcyclohexene-2,6,6-d 6 (2b), 1-trideuteriomethylcycloheptene-2,7,7-d 6 (3b), and 1-trideuteriomethylcyclooctene-2,8,8-d 6 (4b) have been prepared from the corresponding protiated substrates 1a, 2a, 3a, and 4a using a modified HTDA exchange method. The perlabelled analogues of 1a and 2a, 5 and 6, have been synthesized by the same method.