Abstract
An improved method for a suitable derivatization of polyhydroxylated steroids having one or two tert-hydroxyl groups at the 5β-, 14α-, 17α-, 24-, and/or 25-positions by capillary gas chromatography (CGC) is described. By using trimethylsilyl triflate as a silylating reagent and 2,6-lutidine as a catalyst, each of 5β-cholane and 5α-cholestane series of steroids was successfully transformed into trimethylsilyl (TMS) ether derivatives to give a single CGC peak under mild conditions. More bulky triethylsilyl (TES) etherification of 14α- and 17α-hydroxy compounds provided multiple CGC peaks arising from completely- and/or incompletely-derivatized TES ethers accompanied by their thermal elimination products.
