Mechanism of the Birch Reduction The question of why the 1,3-diene is not formed, even though it would be more stable through conjugation, can be rationalized with a simple mnemonic. See examples of this reaction, which is called the Birch Reduction. * The reaction is carried out at … Therefore, it is often necessary to distill the ammonia before using it in the Birch reduction. Benskeser Reduction:reduction of arenes using Li in 1ºamines, ethylenediamine, or a mix of 1º and 2ºamines; more powerful than Birch conditions can lead to reduction beyond dihydro stage and mixture of products Catalytic Hydrogenation: procedes far past Birch reduction Organic Reactions, 1992, 42, 1 Not Discussed in this group meeting: Thus, treatment of 111 with Lawesson’s reagent afforded thiolactam 112 in 76% yield (Scheme 26). Birch Reduction The Birch Reduction offers access to substituted 1,4-cyclohexadienes. * In Birch reduction, aromatic rings are reduced to 1,4-dienes by alkali metals in liquid ammonia. Alkylation of 112 with Et 3 OBF 4 and subsequent reduction with NaBH 4 and methanol furnished tetracycle 113 in 75% yield. * Commercial ammonia often contains iron as impurity. It is a very useful reaction in synthetic organic chemistry. The Birch reduction is an organic chemical reaction where aromatic compoundswhich have a benzenoid ring are converted into 1,4-cyclohexadiene which have two hydrogen atoms attached at opposite ends of the molecule. Here, an organic reduction of aromatic rings in liquid ammonia with sodium, lithium or p… The Birch Reduction Another way of adding hydrogen to the benzene ring is by treatment with the electron rich solution of alkali metals, usually lithium or sodium, in liquid ammonia. The Birch reduction can be classified as an organic redox reaction.