8,9-24,25-Diepoxy-Eupho-lanostan-3,4-olactone

To a mixture of 0.8 g (4.7 mmol) of metachloroperbenzoique acid (mCPBA) and 1.58g (18.8mmol) of sodium hydrogenocarbonate (NaHCO₃) in 15 ml of dichloromethane was added 1 g (2.35 mmol) of 1 in 5 ml of CH₂Cl₂. After being stirred for 18h, the mixture was washed with 20 ml of 10% Na₂CO₃ and then 20 ml of saturated NaHCO₃. The organic layer was dried over Na₂SO₄ and concentrated in vacuum. The yellow residue was purified by silica gel column chromatography using 85 : 15 hexane : ethyl acetate as eluant to give 2 (540 mg, 48.5%).

Mp: 146-148°C.

IR: 1746.

MS: [M+H]⁺ = 473.

¹H NMR (250 MHz, CDCl₃): 2.5 (m, C2-H₂); 0.75 (s, C18- H₃); 0.87 (s, C19-H₃); 0.95 (d, J= 6Hz, C21-H₃); 2.65 (t, J=10Hz, C24-H); 1.25 (s, C26-H₃); 1.27 (s, C27-H₃); 0.79 (s, C28-H₃); 1.3 (s, C29-H₃); 1.32 (s, C30-H₃).

¹³C NMR (62.5 MHz, CDCl₃):35.2 (C1); 36.8 (C2); 175.73 (C3); 85.5 (C4); 50.9 (C5); 18.8 (C6); 28.0 (C7); 68.65 (C8); 69.7 (C9); 37.2 (C10); 21.4 (C11); 28.2 (C12); 44.0 (C13); 49.6 (C14); 30.7 (C15); 29.7 (C16); 47.7 (C17); 15.5 (C18); 20.1 (C19); 35.4 (C20); 18.5 (C21); 35.7 (C22); 30.8 (C23); 49.42 (C24); 58.52 (C25); 24.9 (C26); 24.6(C27); 24.4(C28); 27.9(C29); 15.7(C30).