“…int.) 472 (M + , 3), 454(21), 421(9), 300(20), 285(21), 237 (40), 234 (98), 201 (57), 175 (88), 135 (100);1 H NMR (CDCl 3 ): 0.82, 0.91, 0.91, 0.98, 1.03, 1.67 (each 3H, s), 1.60 (1H, t, J = 10.8 Hz, H-18), 2.98 (1H, ddd, J = 10.8, 10.8, 5.2 Hz, H-19), 4.60 and 4.74 (each 1H, br s); 13 C NMR (pyridine-d 5 ): 14.7 (q, C-27), 16.3 (q, C-26), 17.3 (q, C-25), 18.0 (t, C-6), 19.4 (q, C-30), 22.3 (q, C-24), 25.6 (t, C-2), 28.7 (q, C-23), 29.4 (t, C-21), 30.5 (t, C-15), 32.1 (t, C-16), 35.1 (t, C-1, 7), 36.9 (t, C-12), 37.3 (d, C-13), 37.8 (s, C-10, 22), 39.1 (s, C-4), 42.3 (s, C-8), 42.6 (s, C-14), 46.7 (d, C-18), 48.7 (d, C-5), 48.9 (d, C-19), 55.6 (d, C-9), 56.3 (s, C-17), 70.5 (d, C-11), 75.9 (d, C-3), 110.2 (d, C-29), 149.8 (t, C-20), 181.5 (s, C-28). 3 -Hydroxyolean-12,28-dioic dimethyl es ter (10b) Amor phous; IR (KBr) max : 3505, 3050, 1730, 1667 cm -1 ; EIMS (70 eV) m/z (rel.…”