Organic Syntheses, Coll. Vol. 3, p.234 (1955); Vol. 24, p.38 (1944).

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Organic Syntheses, Coll. Vol. 3, p.234 (1955); Vol. 24, p.38 (1944).

nor-DESOXYCHOLIC ACID

[3,12-Dihydroxy-nor-cholanic acid]

Submitted by Byron Riegel, R. B. Moffett, and A. V. McIntosh.

Checked by Richard B. Turner and Louis F. Fieser.

1. Procedure

A solution of 59.6 g. (0.1 mole) of 3,12-diacetoxy-bisnor-cholanyldiphenylethylene (p. 237) in 60 ml. of chloroform is prepared by warming and poured into a 1-l. round-bottomed flask containing 300 ml. of glacial acetic acid at about 40°. The flask is provided with a stirrer, a thermometer dipping below the surface of the solution, and a dropping funnel, and is surrounded by a water bath through which cold water can be circulated. A solution of 37 g. of chromium trioxide in 30 ml. of water and 200 ml. of acetic acid is added from the dropping funnel at such a rate that the temperature is kept at about 50°; the mixture is stirred and cooled. This operation should require about 10 minutes. When the temperature starts to drop, the water bath is warmed and the temperature is maintained at about 50° for an additional 20 minutes. The solution is then cooled, and the excess chromic acid is destroyed by adding carefully about 30 ml. of methanol, the temperature being kept below 50° (Note 1).

The reaction mixture is concentrated by distillation under reduced pressure. At first the solvent may be distilled rapidly, but, after the mixture becomes syrupy, the distillation should be carried out below 30° until the residue is almost solid. At a pressure of 10 mm. the concentration requires about 2 hours. The residue is diluted with 500 ml. of cold water, which should be added in several portions with thorough shaking to break up all the lumps. The product is collected on a filter and washed with dilute hydrochloric acid

until the filtrate comes through colorless.

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