反应详情

A solution of diethyl azodicarboxylate (1.62 ml) in tetrahydrofuran (5 ml) was added dropwise to a solution of tert-butyl (Z)-2-hydroxyimino-3-oxobutyrate (1.6 g), methyl cis-4-hydroxycyclohexanecarboxylate (1.9 g) and triphenylphosphine (2.7 g) in tetrahydrofuran (20 ml) over 15 min at room temperature. The mixture was stirred for 18h, then the solvent removed under reduced pressure. The residue was chromatographed on silica to give the title compound (0.93 g, 33%) as a colourless liquid. νmax (film) 2950, 1730, and 1690 cm-1. δH (CDCl3) 1.47-1.64 (3H, m), 1.53 (9H, s), 1.56 (3H, d, J 5.3 Hz), 2.05 (2H, m), 2.17 (2H, m), 2.35 (1H, m), 2.37 (3H, s), 3.69 (3H, s), and 4.24 (1H, tt, J 4.1, 10.0 Hz), δC (CDCl3) 25.2, 26.3 (2C), 28.1 (3C), 29.9 (2C), 41.6, 51.7, 82.9, 84.0, 160.6, 175.5, and 193.0. [Mass spectrum +ve ion (ammonia) MH+ (328), MNH4+ (345)].

1. customthe solvent removed under reduced pressure
2. customThe residue was chromatographed on silica