This article describes a highly effective catalytic asymmetric epoxidation method for olefins using potassium peroxomonosulfate (Oxone, Dupont) as oxidant and a fructose-derived ketone (1) as catalyst. High enantioselectivies have been obtained for trans-disubstituted and trisubstituted olefins which can bear functional groups such as tributylsilyl ether, acetal, chloride, and ester. The enantiomeric excesses for cis-olefins and terminal olefins are not high yet. The current epoxidation shows that the catalyst efficiency is enhanced dramatically upon raising the pH. Mechanistic studies show that the epoxidation mainly proceeds via a spiro transition state, which provides a model for predicting the stereochemical outcome of the reaction. The planar transition state is likely to be the main competing pathway. The extent of the involvement of the planar mode is subject to the steric effect of the alkyl groups on the olefins.

An Efficient Catalytic Asymmetric Epoxidation Method

http://www.jbc.org/content/247/10/3353.full.pdf

Interaction of Peroxidases with Aromatic Peracids and Alkyl Peroxides PRODUCT ANALYSIS

Carbon-13 nuclear magnetic resonance spectroscopy of naturally occurring substances. Alkaloids

https://escholarship.org/content/qt9qv2x5tn/qt9qv2x5tn.pdf?t=p0fuwq

The Pi electron structure and absorption spectra of chlorophylls in solution

Biochemical significance of porphyrin .pi. cation radicals

In recent years, proton magnetic resonance spectroscopy has been utilized to investigate the nature of the species arising when alkenes are dissolved in solutions containing either silver(I) or mercury(II) ions. We report here on the use of high-resolution nmr spectra of ^(13)C (cmr) in natural abundance in examining such complexes.

Nuclear Magnetic Resonance Spectroscopy. Carbon-13 Spectra of the Silver(l) Complexes of Cyclopentene and Cyclohexene

The natural-abundance ^(13)C nmr spectra of indole, the seven monomethylindoles, and some di- and trimethylindoles have been determined at 15.1 MHz. The chemical shifts of the ring carbons in these compounds were found to range over 50 ppm, and with the aid of complete proton decoupling it was possible to resolve all of the carbon resonances. Single-frequency and off-resonance proton-decoupling techniques were employed to assign the resonances to specific carbons.

Nuclear Magnetic Resonance Spectroscopy. ^(13)C Spectra of Indole and Methylindoles

Mass spectra of metal chelates. I. Substituent effects on ionization potentials and fragmentation patterns of some 1-methyl-3-alkyl-1,3-dione-copper(II) chelates

Richard G. Parker

Papers

Nuclear Magnetic Resonance Spectroscopy. Carbon-13 Spectra of the Silver(l) Complexes of Cyclopentene and Cyclohexene

Nuclear Magnetic Resonance Spectroscopy. ^(13)C Spectra of Indole and Methylindoles

Mass spectra of metal chelates. I. Substituent effects on ionization potentials and fragmentation patterns of some 1-methyl-3-alkyl-1,3-dione-copper(II) chelates

National College for School Leadership Succession Planning Evaluation - Final report

Mass spectra of small-ring heterocycles. I. Some 1-alkyl-2-phenyl-3-aroylazetidines