Estrone → HCID 12134978, compound

Participants

Reaction Steps

Estrone [3-hydroxyestra-1,3,5(10)-trien-17-one, 270 mg, 1 mmol) and 1-adamantanol (170 mg, 1 mmol) were added to anhydrous n-pentane (6 mL) and the stirred mixture was cooled with an ice bath. Boron trifluoride etherate (BF3.EtOEt, 0.4 mL) was added over a 10 minute period. After an additional 15 minutes, the ice bath was removed and stirring was continued for an additional 45 minutes at room temperature. During the 45 minute period, solids present in the reaction mixture were dissolved and a yellow oil formed. Crushed ice was then added while shaking and swirling the reaction flask and a pink solid was formed. The filtered, crude pink product was washed with water until the filtrate had a neutral pH, and then the solid was dried in a vacuum oven at 50° C. The crude pink powder (0.4 g) was purified by flash chromatography (silica gel eluted with 20% ethyl acetate in hexanes) to get the pure product (0.31 g, 76.7%). The product was recrystallized from a mixture of chloroform and isopropyl alcohol and characterized as follows: (i) melting point=322-324° C. (see, e.g., Lunn, W. H. W.; Farkas, E., Adamantyl Carbonium Ion as a Dehydrogenating Agent: Its Reactions with Estrone, Tetrahedron 1969, 24, 6773-76, citing melting point as 295-296° C.); (ii) 1H NMR (CDCl3, 300 MHZ) δ0.94 (s, 3H, C18—CH3), 2.8 (m, 2H, C6—CH2) 4.7 (s, 1H, C3—OH), 6.4 (s, 1H, C4—H), 7.12 (s, 1H, C1—H); (iii) 13C NMR (CDCl3, 300 MHZ) δ13.76, 21.47, 25.93, 26.41, 28.63, 28.95 (3×C), 31.56, 35.81, 36.56, 36.98 (3×C), 38.42, 40.69 (3×C), 44.25, 47.99, 50.35, 116.87, 124.11, 131.59, 134.00, 135.02, 152.44, 221.43. (Chemical Abstracts Registry Number [21003-01-0].)

Provenance & Evidence