Isopropyl nitrate → HCID 9929531, compound

Participants

Reaction Steps

Potassium tert-butoxide (1.70 g, 15 mM) and (20S)-20-hydroxymethylpregn-4-en-3-one (1.65 g, 5 mM) are mixed together in tert-butanol (25 mL), and heated at reflux temperature under argon atmosphere for 75 minutes. Iso-propylnitrate (0.51 mL, 5mM) is then added to the refluxing reaction mixture, resulting in an exothermic reaction. After one minute, the reaction vessel is removed from heat and allowed to cool to room temperature. The cooled mixture is then made acidic by addition of acetic acid (5mL), and stirred overnight. The mixture is then diluted with dichloromethane so as to form a separate phase sufficient to solubilize the synthesized product. Subsequently, the solids are removed by filtration and washed with dichloromethane. The materials in both the filtrate and wash(es) are combined together and concentrated. The residue is then redissolved in dichloromethane, then purified by flash chromatagraphy on silica gel to give (20S)-20-hydroxymethyl-4-nitropregn-4-en-3-one. The crystallization of this material from aqueous acetone gives white needles (m.p. 166-168° C.). IR 3435, 1696, 1623(m), 1633 cm-1MS(CI) 376(100%, M+l), 358(30%, M+l-H2O) 1H-NMR (CDC13) δ 0.73(3H, s, C18 -Me), 1.06(d, C20 -Me), 1.29(s, C19 -Me), 3.38(1H, dd, 1/2·C21 -CH2), 3.64(1H, dd, 1/2·C21 -CH2). Analysis. Calculated for C22 H33NO4 ·(0.2)H20: C, 69.70; H, 8.80; N, 3.62; Found: C, 69.78; H, 9.13; N, 3.40. This compound has the following structure: ##STR10##

Provenance & Evidence