Invention of Synthetic Reactions Based on σ−Bond Activation

Many more reactions are reported that involves both carbanionic and carbocationic species. The reaction of allylic acetate with trialkylaluminum, R3Al, whereby an allylic cation and alanate are produced and the alanate delivers an alkyl anion to the allylic cationic center. The reaction of organoaluminums is well-documented, I am convinced this new point of view, or philosophy, is essential for devising and developing novel synthetic reactions. We have observed that the reaction of trimethylaluminum with diastereometric cyclopropylmethyltype acetates provides the same product, endo-methylated norcarane, and have shown that the reaction1 proceeds via a common cyclopropylmethyl-type carbocationic intermediate (Scheme 1)