| abstract |
A method of purifying 1α-hydroxy-20-methyl-2-methylene-19,24,25,26,27-pentanorvitamin D 3 to obtain 1α-hydroxy-20-methyl-2-methylene-19,24,25,26,27-pentanorvitamin D 3 in crystalline form. The method includes the steps of preparing a solvent of either ethyl formate or a mixture of ethyl formate and hexane, dissolving a product containing 1α-hydroxy-20-methyl-2-methylene-19,24,25,26,27-pentanorvitamin 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 1α-hydroxy-20-methyl-2-methylene-19,24,25,26,27-pentanorvitamin D 3 crystals, and recovering the 1α-hydroxy-20-methyl-2-methylene-19,24,25,26,27-pentanorvitamin D 3 crystals. |