Acetyl chloride → 3alpha-Acetylcholanic acid

Participants

Reaction Steps

To tetrahydrofuran was added 0.1 mole of lithocholic acid and 0.1 mole of triethylamine, and the resulting solution was maintained at a temperature below 4° C. in an ice bath. 0.12 mole of acetyl chloride was slowly added thereto, and the resulting solution was reacted for 8 hours. Thereafter, residual solvent was removed by using a vacuum distillator. A compound was extracted by using ethyl acetate, and washed with water a few times, to obtain 3α-acetylcholanic acid. To tetrahydrofuran was added 0.2 mole of 3α-acetylcholanic acid thus obtained and a slight amount of p-toluensulfonic acid. 0.21 mole of ethylvinylether was added to the resulting solution. Then, the resulting solution was reacted for 12 hours, to obtain 3α-acetylethoxyethyl lithocholate of formula 3 (yield: 70%).

Provenance & Evidence