In a 100 mL round-bottomed flask was 12-(Cholest-5-en-3β-oxy)-3-hydroxydodecanal (1.90 g, 3.25 mmol) dissolved in 1,4-Dioxane (10 ml) to give a colorless solution. MeOH (5 ml) was added slowly and only enough was added to keep the aldehyde in solution. SODIUM BOROHYDRIDE (0.184 g, 4.87 mmol) was added to the stirring solution which was then allowed to stir for 2 hours at room temperature. The reaction mixture was quenched by addition of 1N HCl (2 mL). The mixture was diluted to 100 mL with water and extracted with ethyl acetate (3×50 mL). The organic phase was combined, washed with brine (1×50 mL), dried over Na2SO4, filtered and concentrated to give 12-(Cholest-5-en-3β-oxy)dodecan-1,3-diol (1.85 g, 3.15 mmol, 97% yield) as a colorless wax. 1H NMR (300 MHz, CDCl3) δ0.69 (3H, s); 0.83-2.07 (58H, m); 2.13-2.28 (1H, m); 2.32-2.43 (1H, m); 3.14 (1H, tt, J=11.2, 4.4 Hz); 3.46 (2H, t, J=6.8 Hz); 3.60-4.19 (3H, m); 5.36 (1H, d, J=5.2 Hz).
