James M. Renga -- PhD 1975

Scientific Career

Thesis Title Synthesis of α,β-Unsaturated Carbonyl Compounds Using Organoselenium Reagents.
Research Summary Jim's first project involved a test for cyclic conjugation of carbonium ions in spiro-fused cyclopropane rings. He compared the rates of formation of the cation 1 with 2 and 3. A small rate acceleration of 70 for 2 was found attributable to cyclic delocalization, after correction for the inductive effect of the double bond..

Jim then began a very productive investigation of a number of facets of the use of the selenoxide elimination for the synthesis of enones (first discovered by Ieva Reich). He greatly extended the generality of the synthetic method by establishing the principal side reactions that occurred, and developing experimental protocols that avoided these side reactions.

During these studies he first prepared N,N-dialkylselenenamides, and examined their chemistry.

Jim also investigated the use of bromomethyl selenides as alkylating agents for carbonyl enolates, a reaction later used effectively by Craig Jasperse in his work on selenocysteine analogs.

Papers
  1. "Organoselenium Chemistry. α-Phenylseleno Carbonyl Compounds as Precursors for α,β-Unsaturated Ketones and Esters," H. J. Reich, I. L. Reich and J. M. Renga, J. Am. Chem. Soc. 1973, 95, 5813.

  2. "Enolate Alkylation with Bromomethyl Sulphides: Synthesis of α-Methylene Ketones and Carboxylic Acids," H. J. Reich and J. M. Renga, J. Chem. Soc., Chem. Commun. 1974, 135.

  3. "Organoselenium Chemistry. Conversion of Cyclic Ketones and β-Dicarbonyl Compounds to Enones," H. J. Reich, J. M. Renga and I. L. Reich, J. Org. Chem. 1974, 39, 2133.

  4. "A Test for Cyclic Conjugation Involving the Cyclopropyl Carbinyl Cation," H. J. Reich and J. M. Renga, Tetrahedron Lett. 1974, 2747.

  5. "Organoselenium Chemistry. Conversion of Ketones to Enones by Selenoxide syn-Elimination," H. J. Reich, J. M. Renga and I. L. Reich, J. Am. Chem. Soc. 1975, 97, 5434. PDF

  6. "Organoselenium Chemistry. Preparation and Reactions of Benzeneselenenamides," H. J. Reich and J. M. Renga, J. Org. Chem. 1975, 40, 3313.

  7. "Organoselenium Chemistry. Mechanism and Stereochemistry of N,N-Dimethylbenzene-selenenamide Addition to Dimethyl Acetylenedicarboxylate. Configurationally Labile Olefins," H. J. Reich, J. M. Renga and J. E. Trend, Tetrahedron Lett. 1976, 2217.

  8. "Preparation of beta-Dicarbonyl Enones: 2-Acetyl-2-cyclohexene-1-one," J. M. Renga and H. J. Reich, Org. Synth. 1979, 59, 58.

  9. "Organoselenium Chemistry. Alkylation of Acid, Ester, Amide and Ketone Enolates with Bromomethyl Benzyl Selenide and Sulfide: Preparation of Selenocysteine Derivatives," H. J. Reich, C. P. Jasperse, and J. M. Renga, J. Org. Chem. 1986, 51, 2981. PDF DOI

Current Position Senior Research Scientist, Discovery Process Research
DowElanco Discovery Process


For comments, additions and corrections, send e-mail to Hans J. Reich