Reaction of Dinitrogen Tetraoxide with Hydrophilic Olefins: Synthesis of Citric and 2-Hydroxy-2-methylbutanedioic Acids

Article abstract of DOI:10.1021/jo01290a008

Liquid olefins typically react with N2O4 by free-radical reactions to form dinitro and nitronitrite derivatives.Introduction of hydrophilic substituents into 1-olefins altered the course of the reaction of the olefins with N2O4 in aqueous HNO3.Citric acid was formed in 64 mol percent yield by the reaction of 3-methylene-1,5-pentanediol with N2O4 in aqueous HNO3.Similarly, 2-hydroxy-2-methylbutanedioic acid was made from 3-methyl-3-buten-1-ol in 88percent yield.These results are explained by solution of the hydrophilic olefins in aqueous HNO3-N2O4 and addition of N2O4 to the double bond as NO⁺ and NO3^- ions to yield nitrosonitrates, which react further to give the final products.