ABSTRACT The Diels-Alder reaction has been an area of great research interest with regards to enhancing enantioselectivity in the reaction by use of various catalysts and reaction conditions. INTRODUCTION In organic chemistry, a Diels-Alder reaction refers to a 4, 2 cycloaddition between a diene consisting of alternating double bonds and a substituted alkene (the dienophile) resulting in a substituted cyclohexene system. The reaction is often used to reliably control regioselective and enantioselective aspects in organic synthesis. If specific conditions are applied, these reactions can be reversible, with the reverse reaction referred to as the retro-Diels-Alder reaction. Mechanism, Regioselectivity and Enantioselectivity of the Diels-Alder Reaction
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.
3. To purify and identify the product, recrystallization is used in order to purify the product, then melting point and TLC techniques are used to identify the product. Theory 4. In nucleophilic substitution reactions, there are two possibilities, either Sn1 or Sn2. In this particular experiment, an Sn2 reaction
TLC, NMR, and IR spectroscopy were used throughout the process to identify ferrocene and acetylferrocene in addition to evaluating the levels of purity. Evidence: The objective of our experiments was to prepare acetylferrocene from ferrocene. The overall reaction was carried out using 6.1 equivalents of liquid acetic anhydride to 1.8 equivalents of phosphoric acid and concluded with an aqueous workup with NaOH. The initial reaction mixture containing ferrocene, acetic anhydride, and phosphate acid was mixed on a hot stir plate. During this period, reflux was observed, and the mixture appeared dark brown in color.
CML103 - Term paper Methanol Synthesis Industrial process/chemical synthesized: Today in industries, generally the basis for the manufacture of methanol is synthesis gas (normally called as syn gas). Syn gas is a mixture of carbon-monoxideand hydrogen. By syn gas :- For the production of methanol to be independent of feedstock material, the three steps that can be followed are :- Syn gas preparation, Methanol synthesis and, Methanol purification that contain the reactions given below a.) CO (g) + 2H2 (g) CH3OH (g) H25oC = -90.79 KJ/mol b.) CO2 (g) + 3H2 (g) CH3OH(g) + H2O (g) H25oC = -11.90 KJ/mol c.) CO2 (g) + H2 (g) CO (g) + H2O (g) H25oC = 41.01 KJ/mol The above three given chemical reactions are reversible reactions that is why we must have to control the temp., pressure and syngas mixture for the production of intermediate or products.
Nowadays, as a part of the human activities, CO2 is produced in large amounts due to the industrial activities. There are four main sources responsible for the production of carbon dioxide into the atmosphere: combustion of fossil fuels, transportation and industry. The first source of emission of CO2 is burning of petroleum and fossil fuels. During the process of combustion of fossil fuels, Carbon reacts with the oxygen resulting in the production of Carbon Dioxide. For example, in order to generate electricity, fossil fuels are burned.
During the binding process the substrate requires some assistance in order to bind to the enzyme properly. This is done by several different catalytic mechanism. The most abundant catalytic mechanism is known as the general acid-base catalysis. For this reaction to occur, one of the eight amino acid residues, shown in fig 6-9, will act as a proton donor or a proton acceptor. The amino acid residues known for their acidic form will function as the proton donor and the residues that form a base will act as a proton acceptor.
Introduction The term chromatography actually means colour writing, and signifies a technique by which the substance to be examined is placed in a vertical glass tube containing an adsorbent, the different segments of the substance traveling through the adsorbent at distinctive rates of velocity, according to their degree of attraction to it, and producing bands of colour at different levels of the adsorption column. The substances least absorbed emerge earliest; those more strongly absorbed emerge later. (Wixom et al., 2011) In chromatography of all types, there is a mobile phase and a stationary phase. The stationary phase is the phase that does not move and the mobile phase is the one that does move. The mobile phase moves through the stationary phase picking up the compounds to be tested.
Column It is heart of HPLC system made up of heavy-walled glass tubing or precision-bore stainless steel. The most common type of packing for HPLC columns is finitely divided Silica gel, Alumina and Celite. A second type of packing material is called pellicular, consists of small beads coated with layer of a porous material such as silica gel, alumina or ion exchange resin. 6. Detector This detector is used for measurement of specific physical and chemical properties of the column effluent.
Elution was the main process used in this experiment; there are two types of elution isocratic and gradient. Gradient elution was used in this experiment. Elution is the process of extracting one material from another with the use of a solvent. The eluent is the liquid solvent and the eluate is the product coming out from the chromatograph. Colored eluates were coming out of the column and were collected in separate test