The acylation of 2-trimethylsilylnorbornene 1 in the presence of aluminium chloride gives minor quantities of the expected 2-norbornenyl ketones 4. The formation of 3 and 5 as major products indicates that either α-or β-attack takes place predominantly depending on the nature of the acyl group, and the β-silicon effect is not a decisive factor. The β-silyl cation intermediate 2 mainly leads to nortricyclyl ketones 3 through 1, 3-deprotonation, and the α ...
[Cornelius, Lyndon A. M.; Bone, Richard G. A.; Hastings, Riley H.; Deardorff, Matthew A.; Scharlach, Randall A.; et al. Journal of Organic Chemistry, 1993 , vol. 58, # 11 p. 3188 - 3190]