g (3.1 mmoles) of I11 in 150 ml of dry Eta0 was stirred with 0.55 g (4.9 mmoles) of KO-t-Bu at 0'for 15 min (progress of the reaction was followed by ir spectroscopy). The reaction mixture was filtered through a sintered-glass funnel and the filtrate was removed under reduced pressure at room temperature. The solid residue was recrystallized from heptane to afford 0.51 g (68%) of the aziridinone I: mp 82-83'; ir, 1830 cm-'; nmr, T 7.32 (1 H, s), 7.73-8.42 ( ...