3- 3 Synthesis of 3-epi vitamin D3 metabolites and analogs

摘要

The present invention relates to a process for the preparation of vitamin D ₃ compounds of the following general formula (1):;; Wherein; A is a single or double bond,; B is a single cis-double and trans double or triple bond,; R ₁ and R ₂ are independently hydrogen or C ₁ -C ₄ alkyl,; R ₃ and R ₄ are independently C ₁ -C ₄ alkyl, hydroxyalkyl or haloalkyl.