Phosphate → HCID 15429004, compound

Participants

Reaction Steps

This synthesis is depicted in FIG. 179. To a solution of alcohol 8 (545 mg, 2.0 mmol) in acetone (100 ml) at 0° C. under N2 was added rapidly Jones reagent (i, 1.5 ml, ca. 4 mmol). After 5 min., the mixture was poured into a dilute phosphate buffer (pH 7.2, 1200 ml) and extracted with ether. The extracts were washed with sat. aq. NaCl solution, dried (Na2SO4) and evaporated to give mainly Androsta-5,16-dien-3-one as an oil (567 mg). The crude product was dissolved in THF (7 ml) and reduced with lithium tris (1,2-dimethylpropyl) hydridoborate (c) at 0.55° as described for the preparation of 2. The crude product (530 mg) was chromatographed on silica gel (100 g) with CH2Cl2 /ethyl acetate 4:1 to give 280 mg (51) of pure a-alcohol 7 (eluted first) and 13 mg of 5 starting alcohol 8. A small sample of 7 was recrystallized from acetone/water at RT. M.p. 1380, [8 ]D -77.5° (c-1.2. -IR. (CDCl3): 3580m, 3430m, 1665w, 1590w, -1H-NMR. (360 MHz): 0.80 (s, 3 H); 1.06 (s, 3 H); 4.02 (m, w,8, 1 H); 5.44 (m, 1 H); 5.72 (m, 1 H); 5.86 (m, 1 H).

Provenance & Evidence