Calcium in Liquid Ammonia for the Reduction of Benzyl Ethers. Mechanistic Clues Derived from Chemoselectivity Studies

Article abstract of DOI:10.1021/jo00374a048

Extremely high selectivity was provided by calcium in liquid ammonia in the cleavage of the benzylic carbon-oxygen bond in benzyl ethers containing various other functionalities.Results of controlled experiments indicate that the selectivities offered by the Ca -> Ca⁺ + e^- and the Ca⁺ -> Ca²⁺ + e^- processes are 4.6 and 47 times greater, respectively, than that afforded by the Li -> Li⁺ + e^- process.