Enamine chemistry. Part IX. Synthesis, structure, and spectra of acyclic dienamines; linear versus cross-conjugation
作者:P. W. Hickmott、B. J. Hopkins、C. T. Yoxall
DOI:10.1039/j29710000205
日期:——
formation of an equilibrium mixture of linear and cross-conjugated dienamines, the latter being the more stable thermodynamically. The stereochemistry and spectra of the dienamines and of the corresponding unsaturated ketones formed on hydrolysis are reported, and the course of the conversion of methyl alkyl ketones, and of their monoenamines, into dienamines is discussed.
Aldol condensation of butan-2-one and pentan-3-one on an activated alumina as monitored via in-situ carbon-13 nuclear magnetic resonance spectroscopy
作者:Valerie A. Bell、Robert F. Carver、Cecil Dybowski、Harvey S. Gold
DOI:10.1039/f19848000831
日期:——
Conventional 13C nuclearmagneticresonancespectroscopy is used to monitor the reactions of butan-2-one and pentan-3-one adsorbed on alumina. Both reaction sequences proceed via successive aldolcondensations. The products observed for butan-2-one (5-methyl-4-hepten-3-one and 4-hydroxy-4-methylpentan-2-one) are those expected for homogeneous base catalysis. A J-modulated spin–echo sequence demonstrates
常规的13 C核磁共振波谱用于监测吸附在氧化铝上的丁2-1和戊3-1的反应。两个反应序列均通过连续的醛醇缩合进行。丁-2-酮(5-甲基-4-庚-3-酮和4-羟基-4-甲基戊-2-酮)中观察到的产物是预期用于均相碱催化的产物。甲Ĵ -modulated自旋回波序列表明,5-乙基-4-甲基-5-庚烯-3-酮,将β,γ缩合产物,使用戊烷-3-酮获得。结果表明,常规13 C nmr可以有效地区分表面催化反应的反应途径和产物。
METHODS FOR PRODUCING FUELS, GASOLINE ADDITIVES, AND LUBRICANTS USING AMINE CATALYSTS
申请人:The Regents of the University of California
公开号:US20170327448A1
公开(公告)日:2017-11-16
Provided herein are methods for producing α,β-unsaturated ketones from the condensation of methyl ketones in the presence of an amine catalyst. Such amine catalysts may be supported, for example, on a silica-alumina support. Such amine catalysts may be used in the presence of an additional acid. The α,β-unsaturated ketones may be produced by dimerization and/or timerization of the methyl ketones. Such α,β-unsaturated ketones may be suitable for use in producing fuels, gasoline additives, and/or lubricants, or precursors thereof. The methyl ketones may be obtained from renewable sources, such as by the fermentation of biomass.
Polyalkylhydroxychromene and process for preparing the same
申请人:MITSUI PETROCHEMICAL INDUSTRIES, LTD.
公开号:EP0021827A1
公开(公告)日:1981-01-07
A compound of the formula (1)
wherein R1 and R5 each represents an alkyl group having 1 to3 3 carbon atoms; R2, R3 and R4 each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms and wherein the bonding at the 2-3 position is a single bond and that at the 3-4 position is a double when the substitution of hydroxy group is at the 5-position or the bonding at the 2-3 position is a double bond and that at the 3-4 position is a single bond when the substitution of hydroxy group is at the 7-position:; with the proviso that R2 and R4 should not be a hydrogen atom or an alkyl group simultaneously. Such a compound can be prepared by reacting resorcinol with an aliphatic ketone or a tertiary alcohol or by thermally decomposing polyalkyl (2, 4 - dihydroxyphenyl) hydroxychroman. The compound is useful as a herbicide and fungicide and as an intermediate for preparing agricultural chemicals.
A process for preparing a hydroxyflavan compound which comprises reacting a polyhydric phenol compound of formula (2):
wherein at
least one of W, X, Y and Z is hydroxy;
with a ketone in the presence of (i) an acid catalyst and (ii) water and/or a seed crystal, using an organic solvent which is insoluble in water, produces the hydroxyflavan compound in high yield and with high selectivity while maintaining high conversion of the polyhydric phenol.
一种制备羟基黄烷化合物的工艺,包括使式(2)的多水酚化合物发生反应:
其中
其中 W、X、Y 和 Z 中至少有一个是羟基;
与酮在(i)酸催化剂和(ii)水和/或籽晶存在下,使用不溶于水的有机溶剂,以高收率和高选择性生产羟基黄烷化合物,同时保持多氢苯酚的高转化率。