Mayo, D. W.; Pike, R. M.; Forbes, D. C. “Microscale Organic Laboratory with Multistep and Multiscale Syntheses”, 5th ed. In the reaction of oxidizing isoborneol (shown in figure 1), the alcohol is oxidized to a ketone. You will use this worksheet to record your answers to the In-Lab questions. List a range for each region, in cm-1, and relate each given region to key functional groups in the starting material, product, or both. To learn a versatile reaction for the reduction of a ketone (or aldehyde) to an alcohol. Introduction: The purpose of this lab was to reduce vanillin to vanillyl alcohol. Download and print the worksheet. After the addition of the reducing agent sodium borohydride, the resulting solution was a cloudy white color. d) Is the absence of any peak or peaks informative? Then, camphor was reduced by sodium borohydride to form two products which were isoborneol and borneol. a) What regions of the IR spectrum would you focus on to assess whether or not the desired product 4-tert-butylcyclohexanol was produced from 4-tert-butylcyclohexanone? Copyright © 2011 Advanced Instructional Systems, Inc. and George Wahl and Maria Gallardo-Williams. Terpenes are hydrocarbon terpenoids that contain double bonds. This is because the C=O stretching band observed in the reactant is absent, and instead an O-H stretching band is observed. To further classify, camphor is a 2monoterpene, a 10-carbon compound derived from two isoprene units. What does the spectrum tell you about the progress of your reaction? Course Hero is not sponsored or endorsed by any college or university. Objective: The purpose of this experiment is to reduce ketones, 4-tert-Butylcyclohexanone, to form the alcohol, cis and trans-4-tert-Butylcyclohexanol. Borohydride Reduction of a Ketone: Hydrobenzoin from Benzil The reduction of a carbonyl group in an organic compound can be readily accomplished with a metal hydride, such as lithium aluminum hydride or sodium borohydride. c) What peak or peaks in the spectrum correspond to the circled proton or protons in part (b)? Note: the alcohol O-H proton is NOT observed in this spectrum. It would be further downfield, since it is not surrounded by any neighboring hydrogens. 4. R and R’ is a variety of atoms and groups atom. 2. 1. Include the following information. In other words, do you know if what you expected to happen actually happened in your reaction vial? 3 In the reaction of the reduction of camphor (figure 2) the ketone is reduced to an alcohol by sodium borohydride. INTRODUCTION A ketone is a compound with the structure RC (=O) R’. It helps identify the product as Trans, since in the cis, the O-H peak would be more pronounced and noticeable. The progress of the reaction was followed using TLC. The circle proton corresponds with the H on the axial position next to the alcohol. “4-tert-Butylcyclohexanol, Mixture of Cis and Trans.” Sigma-Aldrich Co. LLC, 2013. Objective: The purpose of this experiment is to reduce ketones, 4-tert-Butylcyclohexanone, to form the alcohol, cis and trans-4-tert-Butylcyclohexanol. Introduction: Camphor and its reduction products, borneol and isoborneol, come from a bicyclic family called terpenes. Experimental Procedure: Experiment 5B was followed as shown in Mayo pages 158-162, with the following modifications to the procedure: a) The reduction of 4-tert-butylcyclohexanone with sodium borohydride is a stereoselective reaction. What does this mean, in terms of the products that were isolated? The reaction mixture spot separated into only two spots, the first spot was an intense light blue color and the second spot was a small light greenish color. 158-162. 3. The TLC analysis supports this, since the trans-4-tertbutylcyclohexanol had a more intense spot than the cis-4-tertbutylcyclohexanol product, which would indicate that the Trans product had a higher concentration in the reaction mixture. The usual procedure (and the one employed in thi sex periment) involves dissolving the borohydride in 95% ethanol and adding the carbonyl compound to this solution. The alcoholic reactions products are isolated by liquid-liquid extractions techniques and purified by preparative gas chromatography.