Electron ionization mass spectral fragmentation of some isoprenoid glycidic ethers

The electron ionization (EI) mass spectra of Z- and E-2,3-epoxy-3,7,11,15-t etramethylhexadecan-1-ol trimethylsilyl ethers are reported. These compound s present interesting fragmentation processes involving notably a transannu lar cleavage of the epoxide ring after transfer of the trimethylsilyl group . These pathways have been substantiated by deuterium labelling and compari son with the El mass spectra of the isomeric 1,2-epoxy-3,7,11,15-tetramethy lhexadecan-3-ol trimethylsilyl ether and of the corresponding methyl ethers . Copyright (C) 2001 John Wiley & Sons, Ltd.