Nitrogen → HCID 54273405, compound

Participants

Reaction Steps

A mixture of methyl 7-hydroxy-7-methylchol-5-en-24-oate (8) (2.0 g, 4.78 mmoles), aluminum isopropoxide (1.17 g, 5.72 mmoles), 2-butanone (8.6 ml, 96 mmoles) in toluene (40 ml) was heated at 80° in a N2 atmosphere for 6 hrs. About 15 ml of solvent was distilled from the reaction mixture at atmospheric pressure. Toluene (30 ml) was added, and the mixture was extracted with 3N HCl (2 times), H2O (3 times) and dried with MgSO4. Evaporation in vacuo gave 1.7 g of an orange oil that was purified by flash chromatography on silica gel with hexane-EtOAc (7:2 and 2:1) to give 0.62 g of pure 9 as a colorless syrup. NMR (CDCl3): δ 0.76 (s, 3H, 18-Me); 0.94 (d, 3H, 20-Me); 1.08 (s, 3H, 19-Me); 3.67 (s, 3H, CO2Me); 5.59 (s, 1H, 4-H); 5.95 (s, 1H, 6-H).

Provenance & Evidence