“…Enantiomeric excess (ee) was determined by chiral HPLC [Daicel Chiralpak AD-H column], 80.0% n -hexane/i-PrOH, 1.0 mL min −1 ; t major = 12.33 min; t minor = 20.59 min; λ = 254 nm; 81% ee; [ α ] 20 D = +19.55° ( c 0.06, CH 3 OH); [ref. 97 [ α ] 24 D = +20.4° ( c 1.0, MeOH)]; 1 H-NMR (500 MHz, DMSO- d 6 ): δ (ppm) = 7.48–7.45 (m, 2H, Ar–H), 7.33–7.30 (m, 2H, Ar–H), 7.28 (s, 1H, Ar–H), 7.25 (s, 2H, NH 2 ), 7.20 (td, J = 7.7, 1.3 Hz, 1H, Ar–H), 7.15 (dd, J = 7.4, 1.3 Hz, 1H, Ar–H), 7.00 (td, J = 7.5, 1.0 Hz, 1H, Ar–H), 6.86 (d, J = 7.7 Hz, 1H, Ar–H), 5.00 (d, J = 15.8 Hz, 1H, CH 2(a) Bn), 4.78 (d, J = 15.8 Hz, 1H, CH 2(b) Bn), 3.78 (q, J = 7.1 Hz, 1H, CH 2 CH 3 ), 3.52 (dd, J = 10.8, 7.1 Hz, 1H, CH 2 CH 3 ), 2.34 (s, 3H, CH 3 ), 0.58 (t, J = 7.1 Hz, 3H, CH 2 CH 3 ); 13 C-NMR (126 MHz, DMSO- d 6 ): δ (ppm) = 177.20, 164.38, 159.19, 158.86, 142.77, 136.19, 133.65, 128.40, 127.55, 123.34, 122.73, 117.57, 108.91, 104.55, 60.11, 56.12, 48.52, 43.39, 18.65, 13.08. All the analytical data are well in agreement with the reported literature.…”