Unsaturated nitriles: stereoselective MgO eliminations.
Alpha,beta-unsaturated nitriles are readily synthesized by eliminating MgO from beta-hydroxynitriles. Deprotonating acyclic, and cyclic, beta-hydroxynitriles with excess MeMgCl smoothly generates dianion intermediates that eject MgO with concurrent formation of alpha,beta-unsaturated nitriles. Alternatively, sequential addition of lithioacetonitrile and MgBr(2) to aldehydes and ketones generates magnesium alkoxides in situ that eliminate MgO upon addition of MeMgCl. The MeMgCl-induced MgO eliminations smoothly generate alpha,beta-unsaturated nitriles from hindered ketones that are otherwise difficult to synthesize.
Fleming
Fraser F
FF
Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA. fleming@duq.edu
Shook
Brian C
BC
D000447:Aldehydes / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D008277:Magnesium Oxide / Q000737:chemistry*; D009570:Nitriles / Q000138:chemical synthesis*; D013237:Stereoisomerism
D000447:Aldehydes; D007659:Ketones; D009570:Nitriles; D008277:Magnesium Oxide