Reaction Steps
To a vigorously stirred solution of the amine 9 (0.071 g, 0.38 mmol, 1.2 equiv) in CH2Cl2/MeOH (3:1, 5 mL) was added a solution of the aldehyde 8a (0.20 g, 0.33 mmol) in CH2Cl2/MeOH (3:1, 5 mL), dropwise over 20 minutes. The resulting mixture was stirred at it under an atmosphere of nitrogen overnight. 1H NMR showed the reaction to be complete when there was no aldehyde peak present. The solvent was removed in vacuo and the crude imine dissolved in CH2Cl2/MeOH (1:1, 10 mL). The solution was cooled to 0° C. and NaBH4 (60 mg, 1.58 mmol) was added in 15 mg portions over 30 minutes. TLC (10% EtAc/hexane) showed the reaction to be complete after stirring overnight. The solvent was removed in vacuo and the crude oil dissolved in CH2Cl2 (50 mL) and washed with sodium carbonate (10% aq, 3×40 mL). The CH2Cl2 layer was dried over Na2CO3, filtered, the solvent removed in vacuo and the oily residue purified by flash column chromatography (4% MeOH/CHCl3) to give the product 15 as a clear oil (0.18 g, 78%), Rf=0.2 (3% MeOH/CHCl3). 1H NMR (500 MHz, CDCl3) d 6.85 (s, 1H, aryl), 6.80 (m, 2H, aryl), 5.34 (t, 4H, olefinic), 4.78 (br s, 1H, NHCO), 3.97 (q, 4H, OCH2), 3.69 (s, 2H, benzylic), 3.13 (m, 2H, CH2) 2.63 (t, 2H, CH2NH), 2.01 (m, 8H, CH2C═C), 1.80 (m, 4H, CH2CH2O), 1.55 (m, 4H), 1.49-1.12 (m, 57H, 24×CH2, 3×CH3), 0.89 (t, 6H, CH3); 13C NMR (CDCl3) d 156.17, 149.34, 148.29, 133.15, 130.11, 130.00, 120.67, 114.18, 114.08, 79.23, 69.69, 69.52, 54.12, 49.22, 40.80, 32.28, 30.16, 29.92, 29.82, 29.71, 29.67, 28.81, 28.27, 27.68, 27.60, 26.44, 23.09, 14.54; Anal. (C52H94N2O4): C, H, N.
