Reaction Steps
The keto-diester (16) (30 mg, 0.06 mmole) was added to a degassed 10% solution of potassium hydroxide in methanol-water (19:1) (4 ml), and the solution was boiled for 3.5 h under nitrogen. The solvent was removed by evaporation under reduced pressure, and the residue was dissolved in ether. The residue was washed in succession with dilute hydrochloric acid and water, dried, and evaporated to give a residue which was chromatographed on silica (1 g) eluted with ether to give the product (5) (16 mg, 82%), m.p. 113°-4° C. (from ether-light petroleum), νmax 3400 (OH) and 1675 cm-1 (CO), δ (400 MHz) 8.08 (1 H, dd, J 8.5 and 1 Hz, 1-proton), 7.54 (1 H, d, J 3 Hz, 4-proton), 7.12 (1 H, dd, H 8.5 and 3 Hz, 2-proton), 4.27 (1 H, dt, H 10 and 5 Hz, 11-proton), 3.85 (3 H, s, OCH3), 3.79 (1 H, t, J 8 Hz, 17-proton), 2.78 (1 H, dd, J 17 and 2,5 Hz, 12-proton), 2.45 (1 H, t, J 10 Hz, 9-proton), 2.35 (1 H, A portion of ABX system, J 12 and 5 Hz, 7-proton), 2.35 (1 H, B portion of ABX system, J 12 and 5 Hz, 7-proton), 2.18 (2 H, m), 1.96 (1 H, qt, J 14, 10, 5, and 3.5 Hz, 8-proton), 1.86 (2 H, br s, OH), 1.56-1.27 (5 H, m), 0.8 (3 H, s, 18-CH3);
