3.3.1. Camphoratin K (**1**)

Colorless powder; [α] 25 <sup>D</sup> +111.2 (c 0.2, MeOH); IR (KBr) νmax: 3427, 2959, 2942, 2885, 1714, 1643, 1455, 1374, 1266, 1249, 1031, 891 cm−1; UV (MeOH) λmax: 243, 253 nm; ESI–MS *m*/*z* 537 [M + Na]+; HR-ESI-MS *m*/*z* 537.3917 ([M + Na]<sup>+</sup>) (Calcd. for C33H44O4Na: 531.3920); 1H-NMR (CDCl3, 400 MHz) δ 5.05 (1H, dd, *J* = 5.8, 9.4 Hz, H-15), 4.73 (1H, s, H-28), 4.67 (1H, s, H-28), 3.67 (3H, s, OCH3), 3.69 (1H, m, H-21), 3.22 (1H, dd, *J* = 4.4, 11.6 Hz, H-3), 2.22 (1H, sept, *J* = 6.8 Hz, H-25), 2.12 (1H, m, H-16), 2.11 (1H, m, H-23), 2.10 (1H, m, H-7), 2.04 (1H, m, H-11), 2.03 (1H, m, H-7), 2.01 (1H, m, H-20), 1.93 (1H, m, H-12), 1.91 (2H, m, H-11, H-23), 1.73 (1H, m, H-1), 1.63 (2H, m, H-2, H-22), 1.61 (1H, m, H-12), 1.56 (1H, m, H-6), 1.55 (1H, m, H-2), 1.50 (1H, m, H-22), 1.48 (1H, m, H-6), 1.46 (1H, m, H-17), 1.22 (1H, m, H-1), 1.02 (3H, d, *J* = 6.8 Hz, H-26), 1.02 (3H, s, H-31), 1.01 (1H, m, H-5), 1.01 (3H, d, *J* = 6.8 Hz, H-27), 0.99 (3H, s, H-30), 0.97 (3H, s, H-19), 0.80 (3H, s, H-18), 0.80 (3H, s, H-29). 13C-NMR (CDCl3, 100 MHz) δ 171.1 (C-32), 156.1 (C-24), 135.5 (C-9), 132.8 (C-8), 106.4 (C-28), 78.9 (C-3), 76.0 (C-15), 62.0 (C-21), 51.0 (C-13), 50.1 (C-5), 44.4 (C-14), 43.2 (C-20), 38.8 (C-4), 37.1 (C-10), 36.0 (C-16), 35.5 (C-1), 33.7 (C-25), 31.4 (C-23), 30.6 (C-12), 28.2 (C-6), 28.0 (C-17), 28.0 (C-31), 27.7 (C-2), 26.4 (C-11), 21.9 (C-27), 21.8 (C-26), 21.4 (C-33), 20.8 (C-7), 19.1 (C-19), 18.3 (C-31), 18.2 (C-22), 16.4 (C-18), 15.4 (C-29).
