treatment of tertiary and secondary allylicalcohols containing a terminal double bond, and their acetyl derivatives, with triphenylphosphine and iodine under mild conditions leads regiospecifically and in high stereoselectivity to the corresponding primary allylic iodides, which can react ‘in situ’ with diverse nucleophiles. Primary allylicalcohols and benzyl alcohols and acetates are also transformed
Studies on [2 + 3] cycloaddition reaction of nitrile oxides to linear dipolarophiles bearing multiple double bonds
作者:Mirosław Gucma、W. Marek Gołębiewski、Alicja Katarzyna Michalczyk
DOI:10.1007/s00706-016-1797-4
日期:2016.10
selectivity, regioselectivity, and stereoselectivity of [2 + 3] cycloaddition of benzonitrile oxides to polyunsaturated esters were examined. Site selectivity was correlated with electron charges of unsaturated carbon atoms. Structure of the products has been established by an extensive application of 1H and 13C NMR spectroscopy and electrospray ionization mass spectrometry. Graphical abstract
摘要研究了苄腈氧化物与多不饱和酯的[2 + 3]环加成反应的位点选择性,区域选择性和立体选择性。位点选择性与不饱和碳原子的电子电荷相关。产品的结构已通过1 H和13 C NMR光谱学和电喷雾电离质谱的广泛应用而建立。 图形概要
PROCESS FOR THE PREPARATION OF UNSATURATED CARBOXYLIC ACIDS BY CARBONYLATION OF ALLYL ALCOHOLS AND THEIR ACYLATION PRODUCTS
申请人:BASF SE
公开号:US20200055834A1
公开(公告)日:2020-02-20
The present invention relates to a process for carbonylating allyl alcohols at low temperature, low pressure and/or low catalyst loading. In an alternative embodiment, an acylation product of the allyl alcohol is used for the carbonylation. The present invention likewise relates to the preparation of conversion products of these carbonylation products and specifically of (−)-ambrox.
Solid-Phase Selenium-Catalyzed Selective Allylic Chlorination of Polyprenoids: Facile Syntheses of Biologically Active Terpenoids
作者:Alejandro F. Barrero、José F. Quílez del Moral、M. Mar Herrador、Manuel Cortés、Pilar Arteaga、Julieta V. Catalán、Elena M. Sánchez、Jesús F. Arteaga
DOI:10.1021/jo060760d
日期:2006.7.1
Regioselective halogenation of the terminal isopropylidene unit of different acyclic polyolefinic polyprenoids (farnesyl acetate, geranylgeranylacetate, squalene, etc.) using NCS/catalytic polymer-supported selenenyl bromide is described; good to excellent yields are obtained (68−96%). The first applications of this protocol include the concise synthesis of bioactive terpenoids 1−3.
Regioselective Ene-Type Allylic Chlorination of Electron-Rich Alkenes by Activated DMSO
作者:Vera P. Demertzidou、Stavroula Pappa、Vasiliki Sarli、Alexandros L. Zografos
DOI:10.1021/acs.joc.7b01103
日期:2017.8.18
A simple protocol involving the activation of DMSO by chlorotrimethysilane is described for the chemoselective chlorination of polyprenoids. The proposed protocol provides a versatile and scalable alternative to existing routes for accessing useful synthetic synthons for the synthesis of complex terpenoids.