Hydrogen Bromide → Eseroline

Participants

Reaction Steps

Add LiBr (80 g) to 48% aq HBr (40 mL) and water (40 mL) to make a clear solution. To this solution add (-) eserethole (21.31 g, 86.63 mmol) at room temperature under nitrogen with stirring. Heat (90°-100° C.) the brownish clear solution with an oil bath for 5.5 hours. Cool the dark greenish brown solution to room temperature and pour into ice-water (240 mL). To this solution was add 20% LiOH to pH 9-10. Extract the mixture with ethyl acetate (2×150 mL). Wash the combined ethyl acetate solution with brine, dry over potassium carbonate and filter. Concentrate the filtrate (to 100 mL) to provide a residue which contains eseroline (17.76 g, 95% yield, 98.8% purity). This solution was used immediately in the preparation of the title product.

Provenance & Evidence