Reaction Steps
The reaction of hydroxylamine 55 (0.80 g, 2 mmol) with 2-thiophenecarboxaldehyde (64) (0.224 g, 2 mmol) afforded, after workup, a light yellow oil. The crude product was purified by flash chromatography with 2:1 ethyl acetate/hexane as the eluant to obtain 0.86 g (1.73 mmol, 86%) of 75 as a yellow gum: IR (CH2Cl2) 3440, 2940, 1698, 1625, 1560, 1472, 1375, 1298, 1215, 1105, cm-1 ; 1H NMR (CDCl3) δ 1.09 (d, J=6.2 Hz, 3H), 1.21 (d, J=6.2 Hz, 3H), 2.28 (s, 6H), 3.32 (s, 3H), 3.56 (t, J=4.8 Hz, 2H), 4.18 (m, 2H), 4.94 (septet, J=6.2 Hz, 1H), 5.09 (s, 1H), 6.99-8.52 (m, 8H); 13C NMR (CDCl3) δ 19.32, 19.44, 21.99, 22.22, 40.12, 58.85; 62.81, 67.18, 70.74, 102.75, 103.53, 118.83, 120.88, 127.19, 128.53, 129.34, 130.21, 130.29, 131.42, 133.00, 145.12, 145.91, 146.37, 149.97, 167.09, 167.55. Anal. calcd for C26H30N2O6S: C, 62.65; H, 6.02. Found: C, 62.47; H, 6.10.
