3β-Acetoxy-elemo-lanost-8-en-24-one

The sodium periodate is prepared in situ with a equimolecular quantity of soda NaOH (0.5g; 12.50 mmol) and periodic acid H₅IO₆ (2.85g; 12.50 mmol), the mixture is stirred at 0°C. After 15 min, 5 ml of CCl₄, 5 ml of H₃CCN and 93.03mg (0.12mmol) of ruthenium trichloride^1,2 were added. The mixture was stirred during 15min, and then 1.50g (3.12 mmol) of 1³ was added. The reaction was left under stirring at 25°C for 30h, then 20 ml of distilled water was added and the fractional mixture was extracted with the dichloromethane. After filtration on a silica gel column to eliminate RuO₄, the organic layer was recovered, dried by Na₂SO₄ and evaporated under reduce pressure. The residue was purified on silica gel column using hexane: ethyl acetate (97:3) as eluent to give 2 (1.14g, 2.35 mmol) in 76 % yield.

Melting point: 110-111 °C (Hexane)

MS (EI, 70eV): 484 (M^+.).

¹H NMR (300 MHz, CDCl₃) δ(ppm): 4.50 (3H-3, dd: J₁ = 12 Hz, J₂ = 4 Hz); 2.13 (COOCH3, s); 0.76 (3H-18, s); 0.85 (3H-19, s); 0.93 (3H-21, d, J = 6 Hz); 2.60 (2H-23, m); 1.45 (3H-26, d: J = 2 Hz); 0.80 (3H-28, s); 0.95 ( 3H-29, s); 1.05 (3H-30, s).

¹³C NMR (75 MHz, CDCl₃) δ (ppm): 35.03 (C-1); 27.60 (C-2); 81.03 (C-3); 36.18 (C-4); 50.03 (C-5); 37.95 (C-6); 28.07 (C-7); 133.71 (C-8); 134.04 (C-9); 36.3 (C-10) ; 20.25 (C-11); 25.37 (C-12); 44.22 (C-13); 50.22 (C-14); 30.84 (C-15); 30.26 (C-16); 51.15 (C-17); 18.60 (C-18); 18.75 (C-19); 37.23 (C-20); 21.53 (C-21); 37.23 (C-22); 51.32 (C-23); 215.50 (C-24); 31.68 (C-25); 22.74 (C-26); 18.80 (C-27); 15.55 (C-28); 16.45 (C-29); 171.09 (COOCH3); 21.2 (COOCH3).

MS (m/z): 484 (25%), 426 (54%), 298 (65%).