Two new oxindole syntheses

Two oxindole syntheses are described, both starting from ketones, in which the carbonyl carbon becomes C-3 of the oxindole. The first route uses o-lithioformanilide followed by attack with cyanide ion and hydrolysis. The second uses a pinacol-type rearrangement (or the γ-silyl alcohol variation) to create the quaternary centre, and involves an intramolecular displacement of fluoride ion from an unactivated benzene ring by an amide nitrogen to complete the lactam ring. The two routes are stereochemically complementary, giving different spiro-oxindoles from norbornanone.