The Conversion of <i>tert-</i>Butyl Esters to Acid Chlorides Using Thionyl Chloride
作者:Jacob A. Greenberg、Tarek Sammakia
DOI:10.1021/acs.joc.6b02931
日期:2017.3.17
The reaction of tert-butyl esters with SOCl2 at room temperature provides acid chlorides in unpurified yields of 89% or greater. Benzyl, methyl, ethyl, and isopropyl esters are essentially unreactive under these conditions, allowing for the selective conversion of tert-butyl esters to acid chlorides in the presence of other esters.
Formation of a pseudo-β-hairpin motif utilizing the Ant–Pro reverse turn: consequences of stereochemical reordering
作者:Roshna V. Nair、Amol S. Kotmale、Snehal A. Dhokale、Rupesh L. Gawade、Vedavadi G. Puranik、Pattuparambil R. Rajamohanan、Gangadhar J. Sanjayan
DOI:10.1039/c3ob42016g
日期:——
Herein, we report a special case of pseudo-β-hairpin formation by tetrapetide sequences featuring a two-membered Ant–Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverseturn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded
Enantiomerically Pure [2.2]Paracyclophane-4-thiol: A Planar Chiral Sulfur-Based Building Block Readily Available by Resolution with an Amino Acid Chiral Auxiliary
作者:Adrien Vincent、Damien Deschamps、Thomas Martzel、Jean-François Lohier、Christopher J. Richards、Annie-Claude Gaumont、Stéphane Perrio
DOI:10.1021/acs.joc.6b00560
日期:2016.5.6
is an efficient chiral auxiliary for the resolution of (±)-[2.2]paracyclophane-4-thiol. A preparative protocol, based on the conversion into diastereoisomeric thiolesters and separation by two fractional crystallizations and column chromatography, was developed. Deprotection with LiAlH4 allowed isolation of the individual thiol enantiomers in good yield (∼40%) and high enantiomeric purity (ee >93%)
Intramolecular Heterocyclization of o-(1-Cycloalkenyl)anilines: III. Synthesis of Optically Active
4H-3,1-Benzoxazines Based on α-Amino
Acids
作者:Sh. M. Salikhov、R. R. Zaripov、I. B. Abdrakhmanov
DOI:10.1134/s1070428020090183
日期:2020.9
Abstract A new approach has been proposed to the synthesis of opticallyactive 4H-3,1-benzoxazine derivatives based on α-aminoacids. The target products have been obtained by reaction of o-(cyclopent-1-en-1-yl)aniline with N-Boc-protected aminoacids, followed by removal of the protecting group and heterocyclization by the action of dry hydrogen chloride in methylene chloride.
摘要 已经提出了基于α-氨基酸合成旋光的4 H -3,1-苯并恶嗪衍生物的新方法。通过使邻-(环戊-1-烯-1-基)苯胺与N -Boc保护的氨基酸反应,然后除去保护基团并通过在二氯甲烷中的干燥氯化氢的作用进行杂环化,可以得到目标产物。氯化物。
Balenovic; Dvornik, Journal of the Chemical Society, 1954, p. 2976