Calcium Carbonate → HCID 22789221, compound

Participants

Reaction Steps

A solution of 2β-bromo-3α-hydroxy-5α-pregnane-11,20-dione (2.5 g.) in dry dimethyl acetamide (70 ml.) was treated with lithium bromide (9.3 g.) and finely divided calcium carbonate (7.1 g.), and the mixture was stirred on a steam bath for 41/2 hr. The reaction mixture was cooled to room temperature, filtered, treated with 2N HCl to pH 4, and the product was extracted with methylene chloride. The extract was washed with water, dried (Na2SO4), and evaporated in vacuo. The residue (2.3 g.) was subjected to preparative t.l.c. The most polar fraction was 3α-hydroxy-5α-pregn-1-ene-11,20-dione (305 mg., 15%), with a nuclear magnetic resonance spectrum resembling that of the product of Example 17. The least polar fraction, after crystallisation from methyl acetate/petrol, gave 2α-bromo-3α-hydroxy-5α-pregnane-11,20-dione (53 mg.), m.p. 168°-170°, [α]D + 134.5°.

Provenance & Evidence