To a solution of Example 94A (10 g, 33.0 mmol) and ethyl acrylate (14.29 mL, 132 mmol) in dry ethanol (30 mL) was added N,N-diisopropylethylamine (2.85 mL, 16.49 mmol). The mixture was heated to 80° C. and stirred for 4 days. Excess ethyl acrylate and ethanol were removed under vacuum. The residue was purified on a silica gel column (hexane:ethyl acetate=1:3) and then purified again via HPLC (Gilson®, Xbridge™ 50×100 mm column, eluted with pH=10 aqueous ammonium bicarbonate-ammonium hydroxide/acetonitrile, UV=220 nm) to give the title compound. 1H NMR (300 MHz, methanol-d4) δ ppm 1.20 (t, 3H, J=7 Hz) 1.26 (t, 3H, J=7 Hz), 2.52 (td, 2H, J=7, 3 Hz), 2.56-2.65 (m, 1 H), 2.83-3.07 (m, 2 H), 3.17 (ddd, 1H, J=12, 9, 3 Hz), 3.37 (ddd, 1H, J=12, 9, 3 Hz), 3.47-3.61 (m, 2 H), 3.86-3.95 (m, 1 H), 4.06-4.18 (m, 4 H), 4.29 (dd, 1H, J=13, 3 Hz), 6.92-7.01 (m, 2 H), 7.62-7.70 (m, 1 H); MS (DCI) m/z 404 (M+H)+.
