A solution of compound 8c (3.61 g, 8.12 mmol) and benzyl acrylate (2.68 g, 16.52 mmol) in EtOH (abs., 15 mL) was stirred at RT for two days, Ethane-12-diamine (0.50 g, 8.40 mmol) was added and the mixture was stirred for additional two hours followed by up concentration in vacuo and purification on a dry column (EtOAc/heptane, eluting 10% from heptane) to give 4.45 g (91%) of the product as a yellowish to colorless oil. 1