Pheromone study on acarid mites. Part IX. Syntheses of alarm pheromone analogues of the mold mite, Tyrophagus putrescentiae, and their biological activities.
摘要:
针对霉菌螨(Tyrophagus putrescentiae),3, 7-二甲基-(Z)-2-辛烯酸甲酯(II)是除了天然信息素(奈尔酸甲酯 I)外,作为警报信息素最活跃的化合物,其活性与 I 相当(1-10ppm)。为了阐明诱导警报信息素活性的结构要求,制备了16个 I 的类似物,通过改造 II 的结构。为制备3-甲基和3-乙基-(Z)-2-烯酸甲酯,采用了乙氧基或甲氧基碳酰基甲烯三苯基膦与2-烷酮或3-烷酮的威蒂格反应。与2-烷酮的反应产生了约40%的(Z)-2-烯酸酯和约60%的(E)-2-烯酸酯,平均产率为60%。与3-烷酮的反应则得到了56%的(Z)-2-烯酸酯和44%的(E)-2-烯酸酯。在14种(Z)-2-烯酸甲酯化合物中展示了警报信息素活性。研究表明,分子中存在(Z)-烯丙基初级醇酸甲酯基团是诱导信息素活性的关键,且不需要非环状单萜碳骨架。
Highly E-selective solvent-free Horner–Wadsworth–Emmons reaction catalyzed by DBU
作者:Kaori Ando、Kyohei Yamada
DOI:10.1039/c1gc15134g
日期:——
The solvent-free Horner–Wadsworth–Emmons reaction of triethylphosphonoacetate with a variety of aldehydes was catalyzed by DBU in the presence of K2CO3 to give E-α,β-unsaturated esters highly selectively (99:1 for most of the reactions). The reaction with ketones gave trisubstituted olefins with good to high E-selectivity by DBU-Cs2CO3.
这 溶剂无Horner–Wadsworth–Emmons的反应 膦酸三乙酯 与各种 醛类DBU在K 2 CO 3的存在下催化得到E -α,β-不饱和酯类高度选择性(大多数反应为99 :1)。与之反应酮类 给出三取代 烯烃DBU-Cs 2 CO 3具有良好的电子选择性,甚至具有很高的电子选择性。
SUBSTITUTED CYANO CYCLOALKYL PENTA-2,4-DIENES, CYANO CYCLOALKYL PENT-2-EN-4-YNES, CYANO HETEROCYCLYL PENTA-2,4-DIENES AND CYANO HETEROCYCLYL PENT-2-EN-4-YNES AS ACTIVE SUBSTANCES
申请人:BAYER CROPSCIENCE AKTIENGESELLSCHAFT
公开号:US20170210701A1
公开(公告)日:2017-07-27
The invention relates to cyano cycloalkyl penta-2,4-dienes, cyano cycloalkyl pent-2-en-4-ynes, cyano heterocyclyl penta-2,4-dienes and cyano heterocyclyl pent-2-en-4-ynes of general formula (I), or the salts thereof, where [X-Y], Q, R
1
, R
2
, A
1
, A
2
, V, W, m and n have the definitions specified in the description. The invention also relates to a production method for same and to the use of same for increasing stress tolerance in plants against abiotic stress, and/or for increasing the plant yield.
Mechanism of Formation of α,β-Unsaturated Esters in the Reaction of Ethyl Mercaptoacetate Dianion with Carbonyl Compounds
作者:Syuichi Matsui
DOI:10.1246/bcsj.57.426
日期:1984.2
Dianion derived from ethyl mercaptoacetate undergoes aldol type reaction with a carbonyl compound to give an adduct, which exhibited low diastereoselectivity. However, the adducts obtained by the reaction with a variety of aldehydes were subsequently treated with ethyl chloroformate in the presence of trivalentphosphoruscompound to give (E)-isomers of α,β-unsaturated esters in high yields with greater
Synthetic Method to Form 2,2′-Bis(naphthoquinone) Compounds
作者:Vishwajeet Jha、Navneet Goyal、Cheryl K. Stevens、Edwin Stevens、Jayalakshmi Sridhar
DOI:10.1021/acs.joc.7b02501
日期:2017.12.15
We have discovered a transition-metal-free approach to the synthesis of 2,2′-bis(naphthoquinones) using a Diels–Alder reaction of conjugated ketene silyl acetals with benzoquinone. Its monomer analogue can also be synthesized by simply increasing the equivalents of benzoquinone.
Iron-Catalyzed Stereoselective Cross-Coupling Reactions of Stereodefined Enol Carbamates with Grignard Reagents
作者:Ana Cristina Parra Rivera、Raymond Still、Doug E. Frantz
DOI:10.1002/anie.201601899
日期:2016.6.1
A practical and highly stereoselective iron‐catalyzedcross‐coupling reaction of stereodefined enol carbamates and Grignard reagents to yield tri‐ and tetrasubstituted acrylates is reported. A facile method for the stereoselective generation of these enol carbamates has also been developed.