A solution of 4a (4.96 g, 15.67 mmol) and Benzyl Acrylate (14.29 g, 88.09 mmol) in EtOH (abs., 50 mL) was stirred at RT for three days. Ethane-1,2-diamine (2.20 mL, 1.98 g, 32.94 mmol) was added and the reaction mixture stirred for additional two hours. This converts the excess of Benzyl Acrylate into mono-and bis-Michael adducts of Ethane-1,2-diamine that are retained on the column during purification. The solvent was removed in vacuo and the product purified on a dry column (EtOAc/heptane, eluting 10% from heptane) to give the product 1a as a light yellow oil. The yield for this reaction was 8.87 g (88%). 1 A solution of compound 8b (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-1,2-diamine (0.50 g, 8.40 mmol) was added and the mixture stirred for additional two hours followed by concentration in vacuo and purification by dry column chromatography (EtOAc/heptane, eluting 10% from heptane) to give 4.45 g (91%) of the product as a yellowish to colorless oil. 1