Stereospecific Elimination Research Articles

Arylcyclopropane photochemistry. Stereospecific carbene elimination from 1,1-diphenylcyclopropanes

Arylcyclopropane photochemistry. Stereospecific carbene elimination from 1,1-diphenylcyclopropanes

Stereospecificity of isopentenylpyrophosphate isomerase and prenyl transferase from Pinus and Citrus

Isopentenylpyrophosphate isomerases in cell-free extracts from Pinus radiata and from Citrus sinensis eliminate the C-4 pro-S proton from mevalonic acid. Prenyl transferase from Pinus forms geranyl pyrophosphate, neryl pyrophosphate, 2,6 trans, trans farnesyl pyrophosphate and 2 cis, 6 trans farnesyl pyrophosphate from mevalonic acid. The 4-pro-S proton of mevalonic acid is eliminated in the formation of both trans and of cis double-bonds. The pattern is similar for the Citrus enzyme. Isopentenyl pyrophosphate isomerase from Pinus is completely inhibited by 15 m m iodoacetamide, which does not affect prenyl transferase. The pattern is the same for the Citrus isomerase, but less clear for the transferase. Previous work has ruled out direct trans-cis isomerization of C 10 or C 15 prenylpyrophosphates. Alternative mechanisms are proposed for the stereospecific elimination of the 4-pro-S proton of mevalonic acid in the biosynthesis of both cis and trans prenyl pyrophosphates.

Unusual stereospecific elimination of water in the mass spectra of bicyclo[2.2.1]heptan-2-ols

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnusual stereospecific elimination of water in the mass spectra of bicyclo[2.2.1]heptan-2-olsDonald R. Dimmel and Jean M. SeipenbuschCite this: J. Am. Chem. Soc. 1972, 94, 17, 6211–6213Publication Date (Print):August 1, 1972Publication History Published online1 May 2002Published inissue 1 August 1972https://doi.org/10.1021/ja00772a057RIGHTS & PERMISSIONSArticle Views48Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (359 KB) Get e-Alerts Get e-Alerts

Some stereospecific reactions of dibromides from o-cyanocinnamonitriles and related compounds

The αβ-dibromides from o-cyano-trans-cinnamonitrile, the corresponding dicarboxamide and the two cis-amidenitriles are labile and readily undergo stereospecific elimination and/or cyclisation reactions with wate or base. In this way, the cis- and trans-isomers of 3-cyanomethylenephthalide and of α-bromo-o-cyano-cinnamonitrile have been obtained.

Proximity Effect in Arene Pi-Complex Formation

A proximity effect in arene π-complex formation from the reaction system of an aryl Grignard reagent and anhydrous chromic chloride was investigated. The yields of arene π-complexes and any accompanying reaction products were compared by the systematic variation of the aryl Grignard reagent employed. Phenyl Grignard gave the best yield of π-complex followed by the benzyl, mesityl and β-ethyl phenyl analogues. The styryl and phenylacetylenyl analogues did not form any π-complexes. The coupling reaction of benzyl groups gave a new π-complex, π-bibenzyl-π-toluene chromium, along with toluene, bibenzyl and trans-stilbene. Trans-stilbene was found without forming a trace amount of cis-stilbene. A mechanism for this stereospecific and α-hydrogen elimination coupling reaction is proposed.

Stereospecific Elimination and Migration of Deuterium during Hydrolysis of a Substituted Norbornyl Tosylate1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereospecific Elimination and Migration of Deuterium during Hydrolysis of a Substituted Norbornyl Tosylate1Ben M. Benjamin, B. W. Ponder, and Clair J. CollinsCite this: J. Am. Chem. Soc. 1966, 88, 7, 1558–1559Publication Date (Print):April 1, 1966Publication History Published online1 May 2002Published inissue 1 April 1966https://doi.org/10.1021/ja00959a046RIGHTS & PERMISSIONSArticle Views30Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (284 KB) Get e-Alerts Get e-Alerts

The stereochemistry of phytoene biosynthesis

Experiments with carrot root preparations have demonstrated that all the eliminations of hydrogen at C-4 of mevalonic acid during its conversion into phytoene have the same stereospecificity; the 4- R hydrogen is retained and the 4 S hydrogen is eliminated. The same stereospecific elimination is also involved in squalene formation in carrot slices.

Stereospecific Elimination Reactions with Cyclic Ketone Cyanohydrins.

Stereospecific Elimination Reactions with Cyclic Ketone Cyanohydrins.