Double γ-alkylation of allylic phosphorus ylides: a unique access to oxa-bicyclic[3.3.0] diene skeletons
作者:Peng Wang、Saihu Liao、Jian-Bo Zhu、Yong Tang
DOI:10.1039/c3cc45286g
日期:——
A new ylide-initiated tandem cyclization reaction based on γ-dialkylation of allylic ylides has been realized, delivering a series of [3.3.0] oxa-bicyclic dienes in high yields with perfect diastereoselectivity.
Fast and efficient one step synthesis of dienamides
作者:Jennifer E. Mathieson、James J. Crawford、Marc Schmidtmann、Rodolfo Marquez
DOI:10.1039/b901797f
日期:——
A fast and efficient one-step approach to the synthesis of dienamides is reported. This concise methodology relies on the use of imides as reactive intermediates and allows for the preferential formation of Z,E-dienamides in good yields.
Characterization of (<i>E</i>,<i>E</i>,<i>Z</i>)-2,4,6-Nonatrienal as a Character Impact Aroma Compound of Oat Flakes
作者:Christian Schuh、Peter Schieberle
DOI:10.1021/jf051601i
日期:2005.11.1
characteristic cereal-like, sweet aroma of oat flakes, an aroma extract dilution analysis (AEDA) was applied to a distillate prepared by solventextraction/vacuumdistillation from commercial oat flakes. Among the nine aroma-active compounds detected by gas chromatography-olfactometry and AEDA in the flavor dilution (FD) factor range of 4-1024, eight odorants, for example, (E)-beta-damascenone, (Z)-3-hexenal
为了鉴定出具有谷物样特征的燕麦片香气的化合物,将香精提取物稀释分析(AEDA)应用于通过溶剂萃取/真空蒸馏从商用燕麦片制得的馏出物中。用气相色谱-嗅觉法和AEDA检测的9种芳香活性化合物的风味稀释(FD)因子范围为4-1024,其中有8种气味剂,例如(E)-β-大马烯酮,(Z)-3-己烯醛和丁酸,仅显示低FD因子。但是,检测到一种典型的谷物香气,检测到片状甜味,FD系数最高,为1024。通过质谱和核磁共振测量,然后合成(E,E,Z)-2,4,6 -非食用,在空气中的气味阈值极低时为0.0002 ng / L,表现出强烈的燕麦片状气味,被确定为片状的主要气味。通过新开发的稳定同位素稀释分析,使用合成的碳13标记的非芳香族化合物作为内标,每公斤薄片中13杯(E,E,Z)-2,4,6-非芳香族化合物的浓度被测量。模型研究表明亚麻酸是燕麦中非芳香族化合物的前体。
Tandem Michael addition/ylide olefination reaction for the synthesis of highly functionalized cyclohexadiene derivatives
作者:Long-Wu Ye、Xun Han、Xiu-Li Sun、Yong Tang
DOI:10.1016/j.tet.2008.06.048
日期:2008.8
A tandemMichael addition/ylide olefination for the rapid creation of highlyfunctionalized cyclohexadiene is developed. The tandem annulation reactions afford versatile cyclohexadienes in good to excellent isolated yields. This method has been successfully applied to the synthesis of three biologically active molecules.
A new brassinolide inhibitor, named KM-01, was isolated from the culture filtrates of two fungal species, Drechsleraavenae and Pycnoporus coccineus, and the structure with absolute stereochemistry was elucidated as the fatty acid ester of an eremophilane sesquiterpene, bipolaroxin, based on spectroscopic analysis, chemical degradation, and synthesis of the fatty acid.