Studies on the Cu(I)-Catalyzed Regioselective <i>anti</i>-Carbometallation of Secondary Terminal Propargylic Alcohols
作者:Zhan Lu、Shengming Ma
DOI:10.1021/jo0524021
日期:2006.3.31
A highly regioselective Cu(I)-catalyzed anti-carbometallation of secondary terminal propargylicalcohols with 1° alkyl or aryl Grignard reagents affording 2-substituted allylic alcohols was developed. By using this method, optically active allylic alcohols can be prepared from the optically active propargylicalcohols without obvious loss of the enantiopurity. The cyclic organometallic intermediate
Substituent-Control of Two Modes of Intramolecular Reactions of Allyloxy-Silyllithiums and Propargyloxy-Silyllithiums
作者:Atsushi Kawachi、Hirofumi Maeda、Kohei Tamao
DOI:10.1246/bcsj.78.1520
日期:2005.8
Intramolecular reactions of the [(allyloxy)silyl]lithiums and the [(propargyloxy)silyl]lithiums have been investigated. The [(allyloxy)silyl]lithiums proceed in two reaction modes depending on the electronic effect of the substituents at the terminus of the olefin. The [(allyloxy)silyl]lithiums bearing hydrogen, n-C6H13, or trimethylsilyl substituent undergo the [2,3]-sila-Wittig rearrangement to afford the lithium allylsilanolates, while those bearing the phenyl, thienyl, or triphenylsilyl substituent experience the 4-exo-trig cyclization and subsequent 1,3-cycloelimination to give the lithium cyclopropylsilanolates. On the other hand, the [(propargyloxy)silyl]lithiums preferentially undergo the 4-exo-dig cyclization over the [2,3]-sila-Wittig rearrangement in all cases.
Pd-catalyzed selective oxidation of allyl alcohols to access enones and enals
作者:Ruinan Zhang、Xuan Li、Zhenbo Gao
DOI:10.1016/j.tetlet.2022.153976
日期:2022.8
important in synthesis. Here we report a Pd-catalyzed method to selectively oxidize allylic alcohols to enones and enals at room temperature. 27 compounds, including enones, and enals, have been obtained with moderate to excellent yields. Meanwhile, this approach proceeds well on a preparative scale giving a good yield. This work allows the efficient and selective oxidization of various allylic alcohols
Verfahren zur Herstellung von 5-Amino-4-hydroxyvaleriansäure-Derivaten
申请人:CIBA-GEIGY AG
公开号:EP0258183A2
公开(公告)日:1988-03-02
Die Erfindung betrifft neue Verfahren und Zwischenprodukte zur Herstellung von 5-Amino-4-hydroxyvaleriansäure-Derivaten der Formel
worin R¹ Wasserstoff, gegebenenfalls substituiertes Alkyl, Cycloalkyl, Cycloalkylniederalkyl, Aryl, Arylniederalkyl oder den Rest einer natürlichen Aminosäure, R² Wasserstoff, gegebenenfalls substituiertes Alkyl, Cycloalkyl, Cycloalkylniederalkyl, Aryl, Arylniederalkyl, Amino, Hydroxy, Mercapto, Sulfinyl, Sulfonyl oder den Rest einer natürlichen Aminosäure und R³ gegebenenfalls substituiertes Hydroxy oder Amino darstellen, durch sigmatrope Umlagerung eines geeigneten Allylesters, Halolactonisierung der erhältlichen γ,δ-ungesättigten Säure oder eines geeigneten Derivats davon, Austausch von Halogen durch ein stickstoffhaltiges Nukleophil, Lactonringöffnung und Freisetzung der Aminogruppe. Verbindungen der Formel I sind Ausgangsstoffe zur Herstellung von anti-hypertensiv wirksamen Reninhemmern.
Acetyl chloride–ethanol brings about a remarkably efficient conversion of allyl acetates into allyl chlorides
作者:Veejendra K Yadav、K Ganesh Babu
DOI:10.1016/j.tet.2003.09.063
日期:2003.11
AcCl-EtOH transforms primary and secondary allyl acetates into allyl chlorides that retain the olefinic bond in the more stable position. Whereas secondary allyl alcohols also react with almost the same efficacy as the acetates, the reactions of primary allyl alcohols that possess 1,2-disubstituted alkenes are very slow. The products are isolated in high state of purity simply by removal of the volatiles. (C) 2003 Published by Elsevier Ltd.