potassium tert-butylate; triphenylphosphine in THF-d8 (tetrahydrofuran-d8) Kinetics; THF-d8, -43°C, PPh3, t-BuOK, slow warming to room temp. over 4 h; not sepd., detected by (1)H NMR;

t-BuOK-d9 in THF-d8 (tetrahydrofuran-d8) to an argon-flushed NMR tube at -95°C is given THF-d8 and t-BuOK-d9, tube is warmed to -78°C; monitored by (1)H NMR at -63°C;