反应详情

40%-Aqueous formaldehyde solution (4 ml.) and 4%-aqueous sodium hydrogen carbonate solution (6 ml.) were added to a vigorously stirred solution of [7β-formamido-4-(2,2,2-trichloroethoxycarbonyl)ceph-3-em-3-ylmethyl]-triphenylphosphonium bromide (357 mg., 0.5 mmole) in methylene chloride (20 ml.). The two-phase mixture was stirred for 45 minutes, and the organic phase was washed with 2N-hydrochloric acid and water (20 ml. of each), dried (MgSO4), and evaporated to an oil (0.35 g). This was subjected to preparative-layer chromatography on Kieselgel G (Merck PF254+366) using 20% acetone in methylene chloride as eluant to give the title ester as a cream foam (84 mg., 43.5%), λmax. (EtOH) 297.5 nm (ε 10,700), τ (CDCl3) 1.69 (1H, s; CHO), 2.81 (1H, dd, J 11.5 and 18 Hz; CH=CH2), 3.24 (1H, d, J 9 Hz; NH), 4.05 (1H, dd, J 9 and 4.5 Hz; C7 -H), 4.43 (1H, d, J 18 Hz) and 4.55 (1H, d, J 11.5 Hz) (CH=CH2), 4.90 (1H, d, J 4.5 Hz; C6 -H), 4.94 and 5.20 (2H, AB-q, J 12 Hz; CH2CCl3), 6.22 and 6.45 (2H, AB-q, J 18 Hz; C2 -H2).

1. washthe organic phase was washed with 2N-hydrochloric acid and water (20 ml
2. dry with materialof each), dried (MgSO4)
3. customevaporated to an oil (0.35 g)