Cyclization of Cyanoethylated Ketones as a Route to 6‐Substituted Indole Derivatives

δ‐Cyanoketones are quickly cyclized with KOtBu to 3‐aminocyclohex‐2‐enone derivatives, which in turn will give substituted indoles when treated with oxalyl chloride. Thus, 3‐amino‐6,6‐dimethylcyclohex‐2‐enone gave 3‐chloro‐6,6‐dimethyl‐2,5,6,7‐tetrahydroindole‐2,5‐dione, whose structure was corroborated by X‐ray crystallography, whereas the corresponding molecule without the blocking gem‐dimethyl groups, 3‐aminocyclohex‐2‐enone, gave via hydrogen shifts 6‐chloro‐3‐hydroxyoxindole.