| abstract |
A method of purifying (20R,25S)-2-methylene-l9,26-dinor-lα,25-dihydroxyvitamin D 3 to obtain (20R,25S)-2-methylene-l9,26-dinor-lα,25-dihydroxyvitamin D 3 in crystalline form. The method includes the steps of preparing a solvent of methanol and water, dissolving a product containing (20R,25S)-2-methylene-19,26-dinor-lα,25-dihydroxyvitamin D 3 to be purified in the solvent, cooling the solvent and dissolved product below ambient temperature for a sufficient amount of time to form a precipitate of (20R,25S)-2-methylene-19,26-dinor-lα,25-dihydroxyvitamin D 3 crystals, and recovering the (20R,25S)-2-methylene-19,26-dinor-la,25-dihydroxyvitamin D 3 crystals. |