* Reagents : most commonly the base would be the alkoxide, R'O- * The reaction involves an ester enolate reacting with another molecule of the ester. * Remember enolates are good nucleophiles and the ester carbonyl C are electrophilic. * The products of these reactions are ketoesters which are important, useful synthetic intermediates. * Note that the product is the original ester with an acyl group added i.e. an acylation reaction has occurred.
Electron donating substituents attached to the diene, accelerate the reaction as do electron withdrawing groups on the dieneophile . The Alcohol acts as the diene and the anhydride as the dieneophile. The Diels–Alder reaction is a highly stereoselective reaction. In order for the reaction to occur the diene must be in the s-cis formation .The trans, trans-2,4-Hexadiene-1-ol can adopt the cis formation by rotating around a sigma bond while still maintaining Trans stereochemistry . The position of the diene to the dieneophile in the transition state determines the
Since the carbonyl group of the ketone is trigonal planar molecule in its geometry it is able to be attacked from either side of the molecule by the hydride ion. Thus the alcohols that are formed produce a racemic mixture, which contains two enantiomers. The possible products which are formed from the reduction
Because this reaction is reversible, a fractional distillation is necessary to produce cyclohexene, water, and some impurities and a simple distillation is followed to further purify the product. [pic] (Fig. 1- Cyclohexanol dehydrated by sulfuric acid to produce cyclohexene) Procedure: 1. Mix five mL of Cyclohexanol and 2.5 mL of 9M sulfuric acid in a 25 mL flask. 2.
The pyruvate is garter oxidized to yield more ATP What happens to the pyruvate under anaerobic conditions? The pyruvate is converted into lactic acid Diffusion After viewing the animation, answer these questions. Molecules dissolved in a solution are in constant random motion due to their kinetic energy . One result of this motion is that dissolved molecules become evenly distributed throughout the solution . This tendency of molecules to spread out is an example of __diffusion .
Ghostbuster Slime Lab 10/4/2012 Abstract The purpose of this experiment was to observe the physical properties and changes of the creation of a polymer as a result from cross-linking. A borax solution was made and was combined with a polyvinyl alcohol solution. A polymer’s cross-links give them many properties, like bonding ability, elasticity, and viscosity. The amount of water added in the experiment directly affected the viscosity and elasticity of the slime polymer. Too much water added resulted in a high viscosity and low elasticity.
Introduction High performance liquid chromatography (HPLC) is used to separate compounds in a sample, identify compounds and can even be used to deduce the relative amounts of different compounds in a mixture. HPLC works under the same principle as thin layer chromatography using both a stationary and mobile phase. The mobile phase carries the mixture across the stationary phase which is used to separate the compounds. Although in HPLC mobile phase is tailor made to suit the polarity of the analytes. The mobile phase used in this particular experiment was Methanol and 0.1M sodium dihydrogen phosphate at a ratio of 30:70 and a pH of 4.5, slightly acidic.
This is done by a procedure called refluxing. Refluxing is the process of heating a product to the boiling point and re-condensing the vapor continuously. The procedure halogenation is the addition of a halogen to a π bond forming a halo alkane. In this synthetic reaction bromine was used in the process called bromination. The bromine is acting first like an electrophile, and then after bromine has broken the π bond, a carbocation has formed, and a bromide ion has been created, the bromide ion then acts as the nucleophile and forms a bond with the carbocation.
Oxidation of aldehydes yields carboxylic acids. Even air will oxidize an aldehyde (eq 1). H OH | | R-C=O + O2 R-C=O (1) (aldehyde) (from air) (carboxylic acid) Other weak oxidizing agents can bring about this reaction. One of these is Tollens' reagent, a basic (OH- ) solution of the silver
1.3. An Overview for the Synthesis of Tetrahydropyrans, Piperidines and Dihydro-γ-pyrone Derivatives To build this class of heterocycles, many strategies have been developed over the years. The most widely used methods are the Prins cyclization, hetero-Diels–Alder (HDA) cyclization, oxonium-ene cyclization, the intramolecular Michael additions and ring-closing metathesis. Other strategies include electrophile-induced cyclizations of non-activated alkenes and Lewis acid promoted cyclizations of epoxy alcohols/amines. Reported methods used for six membered oxygen and nitrogen ring synthesis have their own advantages and disadvantages.