Neighboring‐Group Participation in the Gas Phase. Loss of benzaldehyde from [(benzyloxy)methyl]dialkylsilyl‐substituted 1,3‐dithianes

Abstract

where a hydride is proposed to be transferred from the benzyl position to a neighboring thionium ion. This would form a particle that could readily lose benzaldehyde as a neutral fragment. The CI-MS results provide an explanation for the unusual instability of (benzy1oxy)methyl-substituted silanes towards acids. In fact, the fonnation of benzaldehyde was established in the decomposition of a (benzy1oxy)metbyl-substituted acylsilane in the presence of Lewis or Brensted acids and ethanethiol. The CI-MS study, therefore, represents a useful method to recognize unusual reactions that are -or might be -important in solution.