After cooking, ketones increase, 3-penten-2-one, 1-penten-3-one and 2-nonanone contributed the good flavor. At the same time, cooking reduced the acids and ringed compounds, which was benifical for the flavor. Although the content of aldehydes didn't change significantly, but the contents of some aldehydes, such as benzaldenyde, heptanal, nonyl aldenhyde lilac aldehyde and 4Z-heptenal, which contributed good flavor to the cooked oyster, increased.Maillard reaction was used to improve the flavor of the flavor product from oyster.

對于生牡蠣一级做a爱过程免费视频韩国，烴類以及1-辛烯-3-醇亚洲√a无码作爱、4-壬烯醛国产精品久久永二区二区、2-辛醛等會對風味產(chǎn)生較大的影響自拍日韩在线视频；在煮制后的牡蠣中，酮類的數(shù)量增加，并大多貢獻出美好的風味一级古装A片，其中3-戊烯-2-酮三级影音先锋、1-戊烯-3-酮、2-壬酮對煮制牡蠣的風味具有好的作用：煮制會使酸類和帶有不良風味的環(huán)狀化合物的數(shù)量減少欧美精品免费a；醛類的數(shù)量和含量在煮制前后雖然沒有太大的改變欧美老妇性爱视频，但是苯甲醛、庚醛全黄视频A片、壬醛无码不卡全黄毛片免费看、丁香醛、4-Z庚烯醛等可以產(chǎn)生良好風味的物質(zhì)含量增加欧美色色色色色图，貢獻了煮制后牡蠣的美好風味十大美女的蛋视频黄色网站a片。

Master the Keto-Enol tautomerism; reactions of enols:α-H substitution reactions;α-halogenation of aldehydes and ketones;α-bromination of carboxylic acids; acidity ofα-H atoms: enolate ion formation; reactivity of enolate ions; alkylation of enolate ions; mechanism of carbonyl condensation reactions;condensations of aldehydes and ketones: the Aldol reaction; dehydration of Aldol products; the Claisen condensation reaction; the Michael addition.

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For the saturated aromatic aldehydes with malononitrile and barbituric acidit, the reaction was found to proceed very efficiently at room temperature giving excellent yields under ultrasonic irradiation, while for α,β-unsaturated aldehydes as well as p-phthalaldehyde with malononitrile and barbituric acid the reaction also proceeded smoothly at room temperature with good yields.

在超聲波輻射下91亚洲国产亚洲综合尤物，不僅飽和芳香醛與丙二腈亚洲国产图片大全视频、巴比妥酸的一鍋反應在室溫下能高收率地進行，而對于α少妇无码视频一级，β-不飽和醛以及二元醛與丙二腈久久久久久九综合久日本精品、巴比妥酸的一鍋反應也能在室溫下順利進行，獲得較高的收率狼人久久伊人无码中文网。

In this catalyst system, the Knoevenagel condensations of a series of aromatic aldehydes with malononitrile or ethyl cyanoacetate were programmed and a mechanism was postulated as well. When aromatic aldehydes reacted with ethyl cyanoacetate, the corresponding alkenes proved to be E-isomers by 1H NMR.

在該反應體系中考察了一系列芳香醛和丙二氰亚洲精品污污网站欧美、氰基乙酸乙酯的縮合反應，并推測了Knoevenagel縮合反應的機理国产黄片视频在线免费观看，芳香醛與氰基乙酸乙酯縮合產(chǎn)物經(jīng)1H NMR檢測為E式烯烴欧美口活视频。

The condensation of aromatic aldehydes with active methylene compounds like malononitrile, cyanoacetamide and ethyl cyanoacetate has been found to proceed very efficiently at room temperature giving excellent yields, but the condensation of heteroaromatic,α,β-unsaturated and aliphatic aldehydes with active methylene compounds proceeded smoothly in 50~65℃ with good yields and the reactions of aromatic, aliphatic ketones as well as p-phthalaldehyde with malononitrile also proceeded in 75~85℃ with moderate yields.

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This work, concentrated on the asymmetric allylation of aldehydes controlled by different chiral auxiliaries prepared from rotational pure tartaric acid, can be divided into three parts.The first part aims to review the developments of chiral drugs and asymmetric synthesis, from which derived the present research topic backgrounds and works.Synthesis and applications of allylation from aldehydes are the second part of the thesis. By optimizing the reaction conditions, such as solvents, temperature, time and chiral auxiliaries like N,N\'-dibenzyl tartamide, N,N\'-p-dimethylphenyl tartamide, N,N\'-o-dimethylphenyl tartamide, N,N\'-o-dichlorophenyl tartamide, N,N\'-a-dinaphyl tartamide, N,N\'-dicyclohexyl tartamide and N,N\'-diphenyl tartamide, ideal experimenttal conditions are obtained according to HPLC monitoring, as well as the auxiliaries\' recoveries experiments. Starting from benzaldehyde and 3-bromopropaldehyde, N,N\'-dibenzyl tartamide is considered the best auxiliary in this reaction.

本文介紹了醛的不對稱烯丙基化反應欧美第一射，以光學純酒石酸為原料，研究了不同構(gòu)型手性配體在醛的烯丙基化反應中的立體選擇性亚洲免费黄色网站入口，全文共分三部分十個章節(jié)：第一部分對當前手性藥物和手性技術進行了概述九九色色视频，并由此展開了本文的研究背景和任務；第二部分為有機合成部分中国国产黄色视频，對醛的不對稱烯丙基化反應進行了深入探討最近中文字幕大全免费1，以苯甲醛為原料對反應條件進行優(yōu)化，在優(yōu)化的反應條件下對制備的七種可回收手性酰胺配體(N-芐基酒石酸二酰胺h视频黄在线观看、N-對甲苯基酒石酸二酰胺性色色色视频、N-鄰甲苯基酒石酸二酰胺、N-鄰氯苯基酒石酸二酰胺黄片视频3级、N-a-萘基酒石酸二酰胺日韩一区二区三区免费体验、N-環(huán)己基酒石酸二酰胺和N-苯基酒石酸二酰胺)進行篩選，優(yōu)化配體回收實驗條件韩国三级在线观影，最終確定出N-芐基酒石酸二酰胺在苯甲醛的不對稱烯丙基化反應中具有較大優(yōu)越性一区二区视频，結(jié)晶回收的手性配體光學純度保持不變。

Thirdly,in the view of some different results between the reaction of complexes(2)3D动漫强奸视频、(3)and[(Me_3Si)_2N]_3LnLi_3 with aromatic aldehydes, the reaction of 2 equiv of aromatic aldehydes with 1 equiv of lithium amide(1) catalyzed by the YCl_3 was subsequently studied,and better yields of the corresponding amides and alcohols can be isolated.These results indicated that the enolate ligand in complexes(2)自拍偷拍欧美色图一区、(3)may have impact on the Cannizzaro disproportionation reaction.

第三，鑒于上述配合物2最近中文字幕视频免费手机版、3和[(Me_3Si_2)2_N]_3LnLi_3與芳香醛反應結(jié)果上的一些差別国模AV影院在线，我們又以三氯化釔為催化劑，將兩當量的芳香醛與一當量化合物1的鋰鹽直接進行反應日韩美女中文字幕高清，結(jié)果以較好的產(chǎn)率得到了相應的酰胺和醇国产另类一区二区在线，這說明配合物2、3中所含的乙烯醇基可能對此Cannizzaro-型歧化反應存在一定的影響永久免费看A片在线看视频欧美。

For very long time, many research groups focus on using more than a stoichiometric amount of a chiral auxiliaries to obtain high enantioselectivity. There were mainly two sorts of processes reported on highly catalytic asymmetric addition of Grignard reagents to aldehydes. The former case was to transform Grignard reagent RMgX into other organometal reagents such as R_2Zn and R-Ti derivatives via complicated procedures at extremely low temperature. The later case was to link a chiral ligand to Mg in the form of organomagnesium amides or use chiral amine ligand catalyzing the alkylation of aldehydes.

格氏試劑對醛的不對稱加成的報道大多需要大量的手性助劑以獲得高的光學活性亚洲欧美乱码一区二区，而高度催化的格氏試劑對醛的不對稱加成主要通過兩種途徑進行：一種是把格氏試劑轉(zhuǎn)化成其他的有機金屬試劑如R_2Zn和R-Ti化合物再對醛進行加成，反應通常在低溫下進行按摩一级毛片真人；另一種是利用手性鎂胺作為中間體或直接用手性胺催化來完成此反應欧美老女人性爱。

Nevertheless, the yield of pinacol was also strongly affected by the steric environment surrounding the carbonyl group. The pinacol coupling of aromatic aldehydes has been achieved with high yields under such a condition. However, the diastereose-lectivities of pinacols were not satisfying. Unfortunately, the ketones and most aliphatic aldehydes appeared inert under the same reaction conditions.

然而， 吶偶合反應的產(chǎn)率受到羰基周圍環(huán)境的立體位阻影響較大，在此條件下久久95国产热情精品国产，鋅粉能有效地促進芳香族醛類化合物進行水相吶偶合反應日韩在线综合专区视频观看，得到的吶醇產(chǎn)率高，但非對映異構(gòu)體選擇性差97免费视频在线观看，而脂肪族醛類化合物得到的吶醇產(chǎn)率較低国产主播在线，在同樣的條件下，酮類化合物不能順利進行吶偶合反應在线成人网站免费。

Carbohydrates are usually defined as polyhydroxy aldehydes and ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones.

碳水化合物通常的定義是多羥基的醛和酮或者水解產(chǎn)生多羥基的醛和酮的物質(zhì)国产九九久久精品视频。