Reaktionsschritte
(1S, 2R, 5S)-(+)-Menthol (7.03 g, 45 mmol), triphenylphosphine (8.65 g, 33 mmol), ethyl (Z)-2-hydroxyimino-3-oxobutyrate (4.77 g, 33 mmol) and diethyl azodicarboxylate (5.7 g, 33 mmol) were reacted by analogy with Example 4a Method 3 to give the title compound (1.37 g, 14%), νmax (CH2Cl2) 2960, 2930, 2870, 1745, 1690, 1370, 1320, 1235, 1075, and 1010cm-1 ; δH (400 MHz, CDCl3) 0.87 (3H, d, J 6.6 Hz), 0.90 (3H, d, J 6.8 Hz), 0.92 (3H, d, J 6.7 Hz), ca 0.9 (1H, m), 1.02-1.12 (2H, m), 1.1-1.3 (1H, m), 1.32 (3H, t, J 7.1 Hz), 1.50-1.65 (2H, m), 1.67-1.78 (2H, m), 2.06-2.18 (1H, m), 2.40 (1H, s), 4.34 (2H, dq, J 7.1 and 1.0 Hz), and 4.70 (1H, broad s); δ13C (100 MHz, CDCl3), 14.24 (CH3), 20.70 (CH3), 20.97 (CH3), 22.26 (CH3) 25.04 (CH2), 25.11 (CH3) 26.06 (CH), 29.10 (CH), 34.77 (CH2), 39.44 (CH2) 46.98 (CH), 61.70 (CH2), 83.43 (CH), 150.28, 161.53, 192.94 [Ammonia CI mass spectrum Found: MH+ (298); MNH+ (315)].
