The Application of C , K for Organic Synthesis : Reduction of Substituted Naphthalenes

Graphite reacts with potassium to form lamellar compounds of different stoichiometry depending on the precise conditions of the preparation.' The best known is the potassium-graphite intercalation compound of stoichiometry C,K, in which each interlayer space in the graphite is occupied by a layer of potassium atoms, i.e. the so-called 'first stage' intercalate. The well defined three dimensional arrangement of potassiumgraphite intercalate, C&, is characterized by a highly ordered structure that enables selective reactivity in comparison to dispersed potassium.' The capability of C8K as a catalyst and reactant in organic synthesis has been a subject of interest.2 This intercalate has already been applied as a reducing agent to a wide variety of reactions, e.g. reduction of double bonds in a,P-unsaturated ketones, carboxylic acids, and Schiff's bases,, alkylation of carbon acids such as nitriles, esters4 and i m i n e ~ , ~ reductive cleavage of carbon-sulfur bonds in vinylic and allylic sulfones and reductive coupling of aromatic acid esters,,