The reaction of cycloalkene with
iodineâcerium(IV) ammonium nitrate (CAN) in
acetonitrileâwater (10:1â1:1) affords the
corresponding trans-iodohydrins and
trans-iodonitrates; when
iodineâcerium(IV) sulfate (CS) in
acetonitrileâwater (10:1) at 50 °C is used,
trans-iodohydrins are obtained preferentially.
Addition of Iodonium Nitrate to Unsaturated Hydrocarbons
作者:U. E. Diner、J. W. Lown
DOI:10.1139/v71-066
日期:1971.2.1
temperature undergoes a trans stereospecific electrophilic addition to alkenes to form (i) iodoaliphatic nitrate esters, (ii) iodoalkane pyridinium nitrates, or (iii) alkene pyridinium iodides depending on the substrate. The addition is sensitive to steric hindrance effects and anti-Markovnikov addition is commonly encountered. In similar additions to conjugated dienes 1,2-additions in a Markovnikov fashion
The reaction mixtures of 5α-cholest-2-ene with iodine-ammonium cerium(IV) nitrate [CAN(IV)] were converted with potassium hydroxide in methanol-water to give the more hindered 2β,3β-diol in high yield. Cyclohexene and cycloheptene similarly reacted to the corresponding cis-diols in good yield. It was found that this reaction intermediate proceeds to give trans-iodoacetate via trans-iodonitrate. This new synthetic method provided several advantages over the Prevost reaction.