Nitrogen → Methyl (3β)-3-hydroxy-7-oxochol-5-en-24-oate

Participants

Reaction Steps

To a suspension of finely ground K2CO3 (3.45 g, 25 mmoles) in 250 ml of methanol was added methyl 3β-acetoxy-7-oxochol-5-en-24-oate (1) (11.1 g, 25 mmoles). After stirring at 45° for 15 minutes in a N2 atmosphere, most of the methanol was removed in vacuo from the clear brown reaction mixture. The residue was suspended in H2O and extracted three times with CH2Cl2. The combined extracts were washed with H20 twice and saturated brine and dried with MgSO4. Evaporation in vacuo gave 10.1 g of nearly pure 2 as a pale yellow solid. The nuclear magnetic resonance data for this and subsequent Examples was taken at 400 MHz in CDCl3 : δ0.68 (s, 3H, 18-Me); 0.94 (d, 3H, 20-Me); 1.21 (s, 3H, 19-Me); 3.66 (s, 3H, CO2Me); 3.68 (m, 1H, 3-H); 5.70 (s, 1H, 6-H).

Provenance & Evidence