“…[α] 20 D 160.5 (c 0.2, chloroform); ν max (film): 2942,2867,1729,1451,1280,1261,1108,1087,1069,1027,757, 710 cm −1 . 1 H NMR (CDCl 3 ) δ: 6.23 (d,1 H,J 5.2 Hz, 8, 79.0, 69.6, 69.5, 69.3, 62.5 (C-5′), 55.3 (C-5), 50.5, 49.9, 47.2, 46.8 (C), 42.5 (C), 40.8 (C), 38.9 (C), 38.7 (CH 2 ), 37.2 (C), 37.0, 35.3 (CH 2 ), 34.2 (CH 2 ), 30.6 (CH 2 ), 29.9 (CH 2 ), 29.0 (CH 2 ), 28.0, 27.4 (CH 2 ), 27.2 (CH 2 ), 25.1 (CH 2 ), 20.9 (CH 2 ), 19.3, 18.5 (CH 2 ), 18.3 (CH 2 ), 16.1,16.0,15.4, 28a-Se-(2,3,4-Tri-O-benzoyl-α-L-arabinopyranosyl)-28a-seleno-28a-homolup-20(29)-en-3β-ol (19). Starting from 12 (110 mg, 0.109 mmol) the title compound was obtained (66 mg, 63%).…”