| 摘要 |
A method of purifying 1a-hydroxy-20-methyl-2 -methylene- 19,24,25,26, 27- pentanorvitamin D3 to obtain 1a-hydroxy-20-methyl-2-methylene- 19,24,25, 26,27- pentanorvitamin D3 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 1a-hydroxy-20-methyl-2-methylene-l 9,24,25, 26,27-pentanorvitamin D3 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 1a-hydroxy-20-methyl-2-methylene- 19,24,25,26,27- pentanorvitamin D3 crystals, and recovering the 1a-hydroxy-20-methyl-2-methylene- 19,24,25, 26,27-pentanorvitamin D3 crystals. |
