Interaction and rearrangement of trimethylsilyloxy functional groups. The structural significance of the m/e 147 ion in the mass spectra of trimethylsil steroidal ethers

Requirements for trimethylsilyloxy group interaction and rearrangement are discussed. It is evident that formation of the m/e 147 ion is a function of the stereochemistry, steric hindrance and separation of the trimethylsilyloxy groups and reflects the stereochemistry of the steroid itself. It is postulated that ring cleavage is not necessarily a prerequisite for the formation of this ion. The occurrence of the m/e 147 ion can be structurally informative in trimethylsilyl derivatives of steroidal alcohols.