メチルステリンのガスクロマトグラフィー (第3報) Δ⁴-ステノールのGLC内分解

抄録

The gas-liquid chromatographic characteristics of 4 kinds of Δ4-stenol (Δ⁴-cholestenol, 4-methyl-Δ⁴-cholestenol, 6α-methyl-Δ⁴-cholestenol, 6β-methyl-Δ4-cholestenol) and also their acetoxy, trifluoracetoxy and trimethylsiloxy (TMS) derivatives have been studied. The Δ⁴-stenols and their derivatives gave two peaks (a and b) which have retention times significantly shorter than would be expected from comparison to other sterols. On the TMS derivatives, the third peak (c) which is less volatile component was also observed. Peak a, b and c were respectively identified to Δ^{2, 4}-diene, Δ^{3, 5}-diene and the original TMS derivative by means of preparative GLC, UV, IR and gas chromatography-mass spectrometry. These results suggested that the Δ⁴-stenols and their derivatives underwent a thermal elimination reaction of functional group at c-3, and yielded unsaturated hydrocarbons (a and b). The structure of resulting hydrocarbons was not affected by the nature of a methyl group in proximity to the Δ⁴-bond.