“…A solution of 100 mg of 2 in 2 ml of ethyl acetate was stirred at reflux for 16 hr. The solvent was then evaporated on a rotary evaporator to give 100 mg of white crystals: sublimed at 40°(0.4 Torr); mp 84-86°; ir (CHC13) 3020, 1450, 1239, 950, and 860 cm"1; NMR (CDC13) 3.4 (s, 4), 3.5 ppm (s, 2); NMR (CgDe) 2.4-2.7 (m, 4), 2.8 ppm (s, 2); mass spectrum m/e (rel intensity) 126 (5), 97 (26), 81 (21), 71 (52), 70 (6), 69 (75), 68 (61), 55 (16), 54 (8), 53 (17), 52 (6), 44 (5), 43 A solution of 2 (-20 mg) in ~0.5 ml of CDCI3 was heated at 45°i n an NMR tube. The NMR spectrum was observed at several times during the reaction and from the integration, the percentage conversion to 3 could be derived ¡time (hr), log [2]): 2.1, 1.93; 3.8, 1.90; 7.6, 1.83; 20.8, 1.52; 24.8, 1.42; 32.9, 1.27.…”