Ozone → HCID 87173610, compound

Participants

Reaction Steps

A solution of lanosterone (4.27 g, 9.11 mmol) in CH2Cl2 (128 mL) was placed in a three-neck round bottom flask equipped with a magnetic stir bar, thermometer, a CaCl2 drying tube and a gas inlet tube. The mixture was stirred and cooled to −50° C., at which point ozone was passed through the mixture for 17 min. The reaction mixture was then purged with argon for 20 min and then concentrated in vacuo to ca. 5 mL. After diluting the crude material with CH2Cl2 (50 mL), the organic phase was then washed twice with water (50 mL) and dried with anhydrous MgSO4. The crude product was concentrated with a rotary evaporator and purified by silica gel chromatography (step gradient of 5:1 then 3:1 hexane/EtOAc) to afford 5 as a white solid (1.578 g, 3.958 mmol, 78% based on an initial purity of 56% for the commercial lanosterol). mp 110-115° C. IR (KBr) νmax 2722, 1725, 1709 cm−1. 1H NMR (CDCl3) δ 9.77 (t, J=1.9 Hz, 1H), 2.57 (ddd, J=7.1, 11.2, 15.7 Hz, 1H), 2.5-2.3 (m, 3H), 2.10-1.18 (m, 19H), 1.11 (s, 3H), 1.09 (s, 3H), 1.06 (s, 3H), 0.90 (d, J=6.3 Hz, 3H), 0.89 (s, 3H), 0.71 (s, 3H). 13C{1H} 6 (CDCl3) δ 217.8, 203.2, 135.2, 133.2, 51.2, 50.3, 49.9, 47.4, 44.5, 41.1, 36.9, 36.1, 36.0, 34.6, 30.90, 30.87, 28.2, 28.11, 26.33, 26.2, 24.3, 21.3, 21.1, 19.4, 18.7, 18.4, 15.9. HRMS calcd for C27H43O2 (M+H)+399.3258. found 399.3258.

Provenance & Evidence