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), and 2 (1,4-dimethyl-3-pentanol). The purpose of this experiment was to understand and become familiar with the reaction mechanisms and be able to observe and compare the product or products for each of the reactions using 13C NMR and IR.
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To prevent the escape of organic vapors, the reaction mixture is cooled with an ice bath before removing the condenser. The next technique used in this experiment was simple distillation. This is a physical separation of the components of the mixture. This technique is accomplished once the drip rate of the product into the collection vessel diminishes considerably. After the reflux and distillation is complete 13C NMR and IR is used to identify the product or products for each reaction. 13C NMR is used to observe the carbon skeleton of an organic molecule. Analysis of this spectrum allows certain stretches to be observed. An IR spectrum has energy measured as frequency recorded on a horizontal axis and intensity of the absorption on the vertical axis. Analysis of the IR allows us to differentiate between certain characteristics and functional groups in organic chemistry.
Results:
1-propanol-1a
Mass of product=1.39
Theoretical yield=5.079g
% Yield=mass of product/theoretical yield x 100
=1.395g/5.079 x 100
% Yield = 27.5%
13C NMR and IR spectrum results for 1a (1-propanol) 13C NMR peaks | 13C NMR descriptions | 11.993 | 1ᵒ alkane –CH3 | 25.589 | 2ᵒ alkane –CH2 | 34.391 | 2ᵒ alkane –CH2 |
IR peaks | IR descriptions | 2921.38 | C-H stretch | 2360.59 & 2341.06 | N/A | 667.94 & 571.62 & 559.56 &565.37 | Fingerprint area |
* The final result and
The objective of this lab was to create a ketone through an oxidation reaction using a using a secondary alcohol and oxidizing agent in order to use that ketone in a reduction reaction with a specific reducing agent to determine the affect of that reducing agent on the diastereoselectivity of the product. In the first part of this experiment, 4-tert-butylcyclohexanol was reacted with NaOCl, an oxidizing agent, and acetic acid to form 4-tert-butylcyclohexanone. In the second part of this experiment, 4-tert-butylcyclohexanone was reacted with a reducing agent, either NaBH4 in EtOH or Al(OiPr)3 in iPrOH, to form the product 4-tert-butylcyclohexanol. 1H NMR spectroscopy was used to determine the cis:trans ratio of the OH relative to the tert-butyl group in the product formed from the reduction reaction with each reducing agent. Thin-layer chromatography was used in both the oxidation and reduction steps to ensure that each reaction ran to completion.
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c/ an assessment of the importance of the technique in developing chemical understanding and as an application in other fields
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This paper will describe the importance of various organic molecules when we follow perquisite steps to unveil them in a few conducted tests.