Reaction Steps
To a vigorously stirred solution of diaminooctane (0.23 g, 1.56 mmol, 5 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 1 hour. The resulting mixture was stirred at RT under an atmosphere of nitrogen overnight. NMR showed the reaction to be complete when there was no aldehyde peak present in the NMR spectrum. 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 sodium borohydride (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 solid dissolved in CH2Cl2 (50 mL) and washed with sodium carbonate (10% aq, 3×40 mL). The CH2Cl2 layer was dried over sodium sulfate, filtered, the solvent removed in vacuo and the solid residue purified by flash column chromatography (1:10:89 NH4OH:MeOH:CHCl3) to give the product 16 as a white solid (0.15 g, 63%), Rf=0.5 (1:10:89 NH4OH:MeOH:CHCl3). 1H NMR (CDCl3) d 6.85 (s, 1H, aryl), 6.80 (m, 2H, aryl), 5.34 (t, 4H, olefinic), 3.97 (q, 4H, OCH2), 3.69 (s, 2H, benzylic), 2.67 (t, 2H, CH2NH2), 2.60 (t, 2H, CH2NH2), 2.01 (m, 8H, CH2C═C), 1.80 (m, 4H, CH2CH2O), 1.54-1.18 (m, 56H, 28×CH2), 0.88 (t, 6H, CH3); 13C NMR (CDCl3) d 149.31, 148.20, 133.55, 130.11, 130.00, 120.59, 114.14, 114.07, 69.70, 69.50, 54.24, 49.83, 42.60, 34.20, 32.28, 30.46, 30.16, 29.92, 29.81, 29.71, 29.67, 27.73, 27.60, 27.22, 26.44, 23.08, 14.53; HRMS (FAB): theory for C51H95N2O2 (M+1), 767.7394; found (M+1), 767.7377. Anal. (C51H94N2O2.0.3H2O): C, H, N.
