Separation of pairs of C‐24 epimeric sterols by glass capillary gas liquid chromatography

Paris of C‐24 epimeric sterols have been very difficult to separate by physical emthods. We report here the partial or complete separation of the trimethylsilyl ethers of nine pairs of C‐24 epimeric sterols by gas liquid chromatography on a glass capillary column coated with SP‐2340. The trimethylsilyl ethers of the epimeric pairs of sterols with saturated side chains and a pair with two double bonds in the side chain were completely separated from each other by GLC. The epimeric pairs with a double bond at C‐22 showed partial separation. The 24β‐epimer with a saturated side chain eluted before the corresponding 24α‐epimer. This order was reversed for pairs of C‐24 epimeric sterol trimethylsilyl ethers containing a double bond in the side chain at C‐22.