Studies on steroids. CCLIII. Capillary gas chromatographic behaviour of diethylhydrogensilyl-diethylsilylene derivatives of stereoisomeric bile acids.
The capillary gas chromatographic behaviour of diethylhydrogensilyl (DEHS) ethers and/or diethylsilylene (DES) derivatives of fifty bile acids including 4- and 6-hydroxylated compounds is described. The methylene unit (MU) values of methyl and pentafluorobenzyl esters of bile acids were determined as their trimethylsilyl (TMS), dimethylethylsilyl (DMES) ethers and DEHS-DES derivatives. The differences in methylene unit values between the corresponding TMS ethers and DMES ethers or DEHS-DES derivatives were used for estimating the number and stereochemistry of hydroxyl groups on the steroid nucleus. On treatment with the silylating agent N,O-bis (diethylhydrogensilyl)trifluoroacetamide, bile acids possessing isolated hydroxyl in addition to diaxial trans-glycol groups were easily converted into the DEHS ehters, whereas those having a vicinal glycol group except for the diaxial group were converted into cyclic DES derivatives. The mass spectrometric properties obtained with negative-ion chemical ionization detection are discussed.
Goto
J
J
Pharmaceutical Institute, Tohoku University, Sendai, Japan.
Teraya
Y
Y
Nambara
T
T
Iida
T
T
D001647:Bile Acids and Salts / Q000737:chemistry*; D002849:Chromatography, Gas; D004987:Ethers / Q000737:chemistry*; D005410:Flame Ionization; D008401:Gas Chromatography-Mass Spectrometry; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
D001647:Bile Acids and Salts; D004987:Ethers; D012821:Silanes