Introduction In this experiment, Conversion of Alcohol to Alkyl Halides and alcohol is converted to an alkyl halide through SN1 or an SN2 mechanism. This is done by using 1-propanol and 2-pentantol with HBr, Hydrobromic acid. Only half of the groups will use 1-propanol, and 2-pentantol. All results are analyzed using NMR and IR. An SN1 reaction, requires two steps. The first step, using an alcohol as an reactant, is the pronation of the –OH group from the R group. This produces a cation intermediate. The cation intermediate is attacked by the –Br group, from HBr. This is the second step. An SN2 mechanism, is only one step, unimolecular , and spontaneous. In an alcohol, the –Br group will attack at the water, H2O, is leaving the reaction. The R group attacks to the Bromine leaving an excess water. Figure 1 Mechanism for 2-Pentantol SN1
Figure 2 2-Pentantol SN2 Mechanism Nuclear Magnetic Resonance, NMR, and Infrared, IR, Spectroscopy are used to determine the structure of unknown compounds. Nuclear Magnetic Resonance allows the student to see the nuclei in a molecule by the usage of light (1). The spectrum shows how carbon can form a number of different bonds hydrogens present in the molecule, double and single. IR spectroscopy gives an idea of the frequency of the molecules through the vibrations of the molecules. Infrared shows how molecules can perform like springs which connects with Hooke’s Law. Hooke’s Law is used to describe the vibrations of springs.
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Conversions of Alcohols to Alkyl Halides: 1-Propanol and 2-Pentanol Introduction One way scientist gets alkyl halides is by using the manipulation of an alcohol. When alcohols are treated with HBr or HCl; they can undergo a nucleophile substation reaction to generate an alkyl halide and water2. Using the structure of the alcohols they are able to use SN1 or SN2 mechanisms. For both these mechanisms though, the –OH group must be pronated shown in Figure 1. R—OH + H—Br + R—OH2 +Br- Figure
Conversion of Alcohols to Alkyl Halides Ankita Patel August 6, 2013 Introduction This lab consisted of the conversion of alcohols into alkyl halides through common substitution methods. These methods include SN1 and SN2 mechanism, both of which can occur for this type of reaction. For both reactions, the first step of protonation will be to add hydrogen to the –OH group and then the rest of the reaction will proceed according to the type of mechanism. SN1 reactions form a cation intermediate
During this experiment, four methods were using in the conversion of alcohols to alkyl halides. These steps were reflux, distillation, separation and drying. This experiment consisted of four major steps: reflux, distillation, separation, and drying. A reflux condenser has water flow from bottom to top with the top being connected to the flask being heated and the bottom connected to an empty flask to collect distillate. Reflux is where the solution is heated to boil and returns the condensing
Conversion of Alcohols to Alkyl Halides Title: Conversion of Alcohols to Alkyl Halides Abstract: In this experiment the conversion of alcohols to alkyl halides are investigated through reflux and simple distillation. These are common procedures used to separate substances. After the reflux and distillation is complete 13C NMR and IR spectrum is used to identify the product or products for each reaction: 1a, 1b, and 2. Every individual in the group was assigned either 1a (1-propanol) or 1b (2-pentanol)
Elimination Reactions of Alkyl Halides Purpose The purpose of this lab is to understand the process of eliminating an alkyl halide to form an alkene. The experiment is carried out by first converting the alcohol, 2-methy-2-butanol, into the alkyl halide of 2-chloro-2-methylbutane that will then be put through dehydrohalogenation that favors elimination reaction (E2) to create a mixture of 2-methyl-2-butene and 2-methyl-1-butene. A fractional distillation will be taken to purify the mixture and an
Elimination Reactions of Alkyl Halides Purpose The purpose of this lab is to understand the process of eliminating an alkyl halide to form an alkene. The experiment is carried out by first converting the alcohol, 2-methy-2-butanol, into the alkyl halide of 2-chloro-2-methylbutane that will then be put through dehydrohalogenation that favors elimination reaction (E2) to create a mixture of 2-methyl-2-butene by alcoholic potassium hydroxide (KOH⁻) base and 2-methyl-1-butene by potassium tert-Butoxide
Conversion of Alcohols to Alkyl Halides Lead Author: Mallori Mays Reviewer: Mallori Mays Editor: Mallori Mays Introduction: In this experiment an alcohol was converted to an alkyl halide by both an SN1 and SN2 reactions. Products were obtained by reflux and simple distillation and collected for running spectroscopy data. There are several different Spectroscopy methods used to observe the effects from when light interacts with molecules, depending on
Scheme – 8: The presence of catalytic amounts of 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate ([Msim]AlCl4) or silica sulfuric acid (SSA) enables an efficient benzylation of a range of aromatic compounds by benzyl acetate under mild conditions. Simple methodology, easy workup procedure, clean reaction and reusability of the catalyst are some advantages.24 Scheme – 9: Shimizu et al. studied benzylation of arenes catalyzed by Ag(I) oxide, Ag(I) ion, bulk silver metal, and silica supported
an alcohol is in the hydroxyl functional group (-OH) is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms. Important alcohols are the simple acyclic alcohols. Of those, ethanol (C2H5OH) is the type of alcohol found in alcoholic beverages, and in common speech the word alcohol refers specifically to ethanol. When it comes to alcohol reactions the functional group of the alcohols is the hydroxyl group –OH. Unlike the alkyl halides
Calculation of Product Distribution of 2-Bromopentane and 3-Bromopentane Amount of Product:.631g 2-Bromopentane(Hydrogen G) Integration:.78 3-Bromopentane(Hydrogen F)Integration:.28 Mole Ratio of 2-Bromopentane to 3-Bromopentane: .78/.28=2.79 which is ~3:1 ratio .75 x .631= .47g 2-Bromopentane .25 x .631= .16g 3-Bromopentane This shows that 2-Bromopentane is the major product. Figure 3: NMR spectrum for the product of 1-propanol and NaBr/H2SO4. In Figure 3, the NMR spectrum that was produced
RING CONTRACTION All the carbons of a ring are equivalent (a ring has no ends like an open-chain compound does),1 ring compounds can be classified as either monocyclic or polycyclic compounds. As the word “contraction” means shrinking, ring contraction can be defined as the process of shrinking larger ring compounds which are less strained into a more strained smaller ring structures. Instead of making small strained ring by chemical reaction which is very strenuous to do, ring contraction is a process