| abstract |
The invention discloses a preparation method of intermediate compound II for preparing vitamin D and its analogues. The method comprises the following steps: taking compound IX as a starting material, adding and reducing ethyl acrylate, and then preparing compound II through reduction, iodation, substitution, alkylation, reduction and deprotection reactions. The present invention also discloses a method for preparing compound II through multi-step continuous operation without separate separation and purification. The invention starts from cheap raw materials, is simple and safe, and is beneficial to industrialized production. |