93% | | Intermediate 12: Intermediate 11 (2.5 g, 10.11 mmol), EDC (5.8 g, 30.30 mmol), and DMAP (494 mg, 4.04 mmol) in an oven-dried flask (200 mE) with a magnetic bar was added anhydrous DCM (50 mE). The mixture was stirred at ambient temperature for 5 minutes to a clear solution. Einoleyl alcohol (6.5 g, 24.20 mmol) was then added and the mixture was stirred at room temperature overnight. The reaction was finally quenched with H20 (50 mE) and extracted with DCM twice (2x50 mE). Organic layers were combined, dried over MgSO4, and filtered. The filtrate was concentrated under reduced pressure. The crude purified by flash chromatography purification system (80 g silica gel colunm) using a gradient of hexane for 2 mm, then 0-25% EtOAc/hexane for 15 mm, then 25% EtOAc/hexane for 5 mm, then 75% EtOAc/hexane for 5 mm under the flow rate at 60 mE/mm. The product fractions were collected and concentrated to yield Intermediate 12 (7.0 g, 93% yield) as a clear liquid. ?H mm (400 MHz, CDC13) oe: 5.38-5.3 1 (8H, m, CH=), 4.28 (1H, bs, NH), 4.08-4.05 (4H, m, OCH2), 2.78-2.75 (4H, m, rrrCHCH2CHrrr), 2.69-2.59 (4H, m, COCH2N), 2.06-2.02 (4H, m, CH2CH2CH), 1.62-1.58 (4H, m, CH2CH2O), 1.43 (9H, s, C(CH3)3), 1.35-1.26 (36H, m, CH2), 0.90-0.86 (6H, m, CH3). |