1,3-Dibromo-5,5-dimethylhydantoin → Androst-5,7-diene-3beta,17beta-diol diacetate

Participants

Reaction Conditions

Reaction Steps

A mixture of androst-5-ene-3β,17β-diol diacetate (3.75 g, 10 mmol), dibromantin (2.03 g, 7 mmol), and sodium bicarbonate (4.54 g, 54 mmol) in hexane (200 ml) is heated under reflux for 0.5 hours. The mixture is then cooled and filtered and the filtrate evaporated to dryness. The residue is dissolved in 50 ml toluene and treated with lithium bromide (2 g) in 5 ml of acetone. The mixture is stirred at 0° C. for 2 hours and then treated with 2 ml triethylamine and 1.5 ml benzenethiol. After stirring at room temperature for 1.5 hours, 100 ml ethyl acetate is added and the organic solution is washed with 1 N hydrochloric acid and water. The organic phase is dried and concentrated. The residue is then redissolved in 75 ml ethyl acetate, cooled to 0° C. and treated with 2.6 g of m-chloroperbenzoic acid for 2 hours. The mixture is washed with 10% sodium bicarbonate solution and then concentrated. The residue is dissolved in 100 ml toluene, treated with triethylamine (3.6 ml), heated at 70° C. for 24 hours, cooled, and washed with water. The organic solution was concentrated and chromatographed to yield androst-5,7-diene-3β,17β-diol diacetate. The diacetate is treated with K2CO3 in a 10:1 methanol:water solution overnight to yield, after extractive workup, androst-5,7-diene-3β,17β-diol.

Provenance & Evidence