“…The residue was purified by fc 26 (m, 3H, 2-CH benzyl , 4-CH benzyl , 6-CH benzyl ), 7.32 (t, J = 7.2 Hz, 2H, 3-CH benzyl , 5-CH benzyl ). 13 C NMR (101 MHz, DMSO-d 6 ): δ (ppm) = 24.6 (1C, CH 2 CH 2 CH 2 OH), 28.7 (1C, CH 2 CH 2 CH 2 OH), 41.3 (1C, NCH 2 Ph), 50.4 (1C, NCH 2 CO), 55.0 (1C, OCH 3 ), 56.5 (1C, NCH 2 PhOMe), 60.01 (1C, CH 2 CH 2 CH 2 OH), 61.9 (1C, NCHCO), 113.8 (2C, C-3 PMB , C-5 PMB ), 127.1 (1C, C-4 benzyl ), 127.3 (2C, C-2 benzyl , C-6 benzyl ), 128.3 (2C, C-3 benzyl , C-5 benzyl ), 128.9 (1C, C-1 PMB ), 130.0 (2C, C-2 PMB , C-6 PMB ), 137.2 (1C, C-1 benzyl ), 158.7 (1C, C-4 PMB ), 170.1(1C, NCH 2 CO), 172.7 (1C, NCHCO). IR (neat): v˜(cm À 1 ) = 3390 (OH), 2935 (C-H Benzyl-4-(4-methoxybenzyl)-3,5-dioxopiperazin-2-yl] propanal (31) The primary alcohol 29 (0.77 g, 2.0 mmol) was dissolved in CH 2 Cl 2 (50 mL) and Dess-Martin-Periodinane (1.02 g, 2.4 mmol) was added.…”