Aldehyde Essays

experiment is the Wittig reaction and the Horner-Wadsworth-Emmons modification. The Wittig reaction involves a reaction between an aldehyde or ketone and ylid, which is also referred to as the Wittig reagent. The Wittig reagent is synthesized from a phosphonium salt and a strong base (Wittig Reaction, 2006). The reaction between the Wittig reagent and the ketone or aldehyde is a nucleophilic substitution; the carbon double bonded to the oxygen in the carbonyl is replaced with a carbon double bonded to

Diels-Alder Reaction: Synthesis of 9, 10 dihydroanthraceno-9, 10-endo-α,β-succinic anhydride Introduction: For this experiment, a Diels-Alder reaction was performed. The concept of this reaction involves two compounds, one of which is an electron donating group and the other is an electron withdrawing group (Weldegirma). These two compounds are referred to as the diene and dienophile respectively (Weldegirma). The conditions for this reaction to take place generally require a fair amount of heat

Results and discussion In this research, a diene (tetraphenylcyclopentadienone) was reacted with three alkyne dienophiles (acetylene dicarboxylate, diphenyl acetylene, and benzyne) to form tetraphenylphtalate, hexaphenylbenzene, and tetraphenylnaphthalene respectively. On the other hand, the diene(anthracene) was reacted with the dienophile(benzyne) to form triptycene. In the first reaction, diene (tetraphenylcyclopentadienone) interacted with the dienophile(acetylene dicarboxylate) to produce

Discussion In this experiment, anthracene and maleic anhydride were reacted in solution to produce a single organic product in crystal form. Anthracene is composed of a 3 carbon rings where the first ring has a 3 pi bonds while the other two has 2. Also, the double bonds are separated by single sigma bonds, which conjugate the double bond. Maleic anhydride has a five-membered ring with ring’s oxygen atoms bonded to two acyl group, ester R-COO. The abundant of esters, which serves as the electron

Equ 13. 4-(5-nolyl)-Pyridinum Cation Containing CILs Catalyzed Aldol Reactions Equ 14. Amide Functionalized Proline based CILs Organocatalyst for Aldol Reactions 3.4. Asymmetric Diels-Alder reaction. In 1997, Howarth and his group80 reported first, the asymmetric Diels-Alder reaction by using dialkylimidazolium salts (chiral and achiral) as efficient organocatalyst between crotonaldehyde or methacrolein and cyclopentadiene. The enentiomeric excess was less than 5% and no such diastereoselectivity

LBYCH63, EA 2, Group # 6 Experiment #8: Aldehydes and Ketones Ong Hian Huy, Tiffany Joy Sir Glenn Kelly U. Tan November 11, 2014 November 25, 2014 Abstract 　　Aldehydes and ketones are two similar functional groups containing the carbonyl group. In this experiment, the main objectives are to be able to do qualitative tests on the samples, to be able to write the respective correct chemical reactions for each sample on each test, and to be able to differentiate aldehydes and ketones from one another and

ANALOGUE PREPARATION WITH AROMATIC ALDEHYDE when aromatic aldehyde is used, magnesium is added to anhydrous methanol or ethanol (4 eq relative to cytosine) and heated until complete dissolution of magnesium filings and add 2 mmol of cytosine, followed by the aromatic aldehyde in the amount of 4-6 eq, minimum of 4 eq relative to cytosine, the reaction mixture is heated up to 45-65°C for at least 3 hours, and later, a reducing agent, preferably NaBH(1 eq relative aldehyde) ,is added to the cooled mixture

fields. In manufacturing cyclodextrins, a reasonable assumption is that the catalytic group is better placed at the secondary rim of CDs since this opening is wider and therefore more likely to bind the substrate. Generally, CDs with one to four aldehyde groups attached to the secondary rim are the most powerful artificial amine oxidase catalysts. Oxidation of

condensation of acidic anhydride and aldehyde in the presence of weak base (i.e. Sodium and potassium salt of the acid or trimethylamine) to give unsaturated carboxylic acid.(Equation-1)[1].In 1968 Perkin described the very first example of such type condensation reaction, involve the synthesis of coumarin by condensing the sodium or potassium salt of salicylaldehyde with acetic anhydride (Equation-2)[2].Generally such type of reaction is only applicable to aromatic aldehyde and useful for the preparation

detail, the Prins cyclization of homoallylic amines takes place in a fashion similar to that of homoallylic alcohols, whereby the non bonding electrons on the nitrogen initiate the sequence of reaction steps by attacking the electrophilic site of the aldehyde activated by an acid catalyst. The key intermediate of the aza-Prins cyclization is an iminium ion, in analogy to the oxonium ion. Compared to classical Prins cyclization, examples of aza-Prins cyclization using iminium ions leading to nitrogen-containing

In this experiment, two alcohols, 1-propanol and 2-propanol, were oxidized through combining each with an excess amount of chromic acid solution. The purpose for conducting this experiment was to determine the reaction rate constant at which aldehydes and ketones formed from the respective oxidation of 1-propanol and 2-propanol. From this value, the half-life of the alcohol during the reaction could be derived. The progress of the reaction was tracked through the color change of the solution through

each product is formed. In a Wittig reaction, an aldehyde or ketone is reacted with a ylide produced from an SN2 reaction with a phosphonium salt. A ylide is a molecule that is neutral overall, but contains neighboring atoms that have opposite charges. A Wittig reaction works when the negatively charged carbon attached to the phosphorous atom in the ylide donates its lone pair to the electrophilic carbon in the carbonyl in either the ketone or aldehyde, depending on which molecule is being used. The

3) The method used was the liquid/liquid extraction because it was able to separate the non polar product in the organic hexane layer and remove the impurities in a polar water layer. This process was repeated numerous times to get rid of as many impurities as possible. After separation, DME was added to the organic layer to remove water impurities which then was further purified by roto-vaporation. This technique also was useful in removing impurities and to separate the liquids from the product

Aldol condensation In the aldol condensation the α-carbon of one aldehyde or ketone molecule adds to the carbonyl carbon of another. The base is most often used is -OH. The product is a β-hydroxy aldehyde or ketone, which in some cases is dehydrated during the course of the reaction. Even if the dehydration is not spontaneous, it can usually be done easily, since the new double bond will be in conjugation with the C=O bond.   Ritter Reaction Alcohols is converted by a strong acid to a carbocation

1- a. One aldehyde gives a positive iodoform test. Which one is it? • Ethanal b. Explain why ethanal gives a positive iodoform test. • Ethanal is the only aldehyde to give a the positive result because the reaction requires a methyl group connected to a carbon atom with a keto or an OH- substituent. 2- In semicarbazone formation only one of the two –NH2groups in semicarbazide undergoes nucleophilic addition to the carbonyl group. Explain the difference in the reactivity of these two –NH2 groups

tryptamine 70 and aldehyde 71 were reacted in the presence of catalytic amounts of diphenyl phosphate (DPP, 5 mol%), to ensure catalysis of the Pictet–Spengler reaction and various catalyst 72 in dichloroethane at

with long chain fatty aldehyde to give peroxyhemiacetal intermediate. This breaks down to give long chain acid and the intermediate hydroxyflavin in a high energy electronically excited state. One photon is produced for every four molecules of FMNH2 oxidized. In the living cell, light is produced continuously, the oxidized FMN formed in the reaction is reduced again by pyridine nucleotide. Similarly, the myristic acid product is converted back to the corresponding aldehyde by enzymes of a specific

The purpose of this experiment was to perform a Wittig reaction using two different methods: In method I, 250 mg aldehyde was mixed with 785 mg phosphonium salt in 5 M NaOH solvent. This mixture was stirred for thirty minutes and filter by vacuum filtration for the product. In method 2, 250 mg of aldehyde, 785 mg, benzyltriphenylphosphonium chloride, and 380 mg potassium phosphate tribasic were homogenize with a pestle and mortar. Vacuum filtration was also used in this method to attain the product

less harmful than tobacco cigarettes and as a result of this reduce the risk of cancer in smokers. E-cigarettes also only produce aldehydes, an organic compound formed by the oxidation of alcohols, under certain conditions while tobacco cigarettes produce aldehydes when one is lit. “Under certain conditions, e-cigarettes may release high levels of aldehydes, aldehydes including Formaldehyde’(Methanol)`are released in tobaccos and contribute to its toxicity. Formaldehyde may be released when the e-liquid

those sugars that cannot be hydrolyzed into simpler carbohydrates. They may be classified as trioses, tetroses, pentoses, hexoses, or heptoses, depending upon the number of carbon atoms, and as aldoses or ketoses, depending upon whether they have an aldehyde or ketone group. Monosaccharides are colorless, crystalline solids that are freely soluble in water but insoluble in nonpolar solvents. Most have a sweet taste. The backbones of common monosaccharide molecules are unbranched carbon chains in which