Sterically crowded trialkylsilyl ether derivatives for the analysis of steroid metabolites

The applications of sterically crowed trialkyksilyl ether derivatives to the analysis and characterization by thin-layer chromatography, gas chromatography and mass spectrometry, of metabolites of 2alpha, 3alpha-cyclopropano-5alpha-androstan-17beta-ol in the rabbit are described. These derivatives are complementary to the familiar trimethysilyl ether derivatives, but have greater hydrolytic stability (an advantage for TLC), generally give better GC separations, and have characteristic mass spectra. Isomer differentiation by GC and MS is also more readily achieved than via the TMSi ether derivatives. These properties should make SCTASi ethers useful derivatives for studies of steroid metabolism.