Unimolecular and Bimolecular Substitution Reactions with Alcohol Containing Compounds
Carmela Verderame, Katie Gao, Christine Yang
Department of Chemistry and Chemical Biology, IUPUI, 402 N. Blackford St., Indianapolis, IN 46202
gcbose@iupui.edu
There are three reactions with alcohol containing groups, on primary and secondary carbons reacting with halide groups that have been investigated through experimental testing. The pathway for substitution varied depending on the structures and nucleophiles. Variables like the position of the primary carbon or the most or least substituted carbon, dictated whether the reaction would be carried out via Sn1 or Sn2 reaction mechanism. The following data shows the findings that demonstrate the proper…show more content… To further confirm which mechanism was utilized, a gas chromatography, Infrared Spectroscopy, and 1H NMR were conducted. With these instruments, we are able to identify functional groups, percent composition, and the location and coupling of hydrogens.
The three reactions above contain an alcohol electrophile (leaving group) and a strong nucleophile to replace it. A variety of lab instruments and processes are conducted to get the desired product. There is a wide range of experimental paths and substitutions that carbons can undergo. Additional building blocks to more complex mechanisms include reactions such an Elimination or addition, each type utilizes different reagents with the same starting material to achieve different products. The chosen reactions were selected to focus specifically on sp3 hybridization of the alcohol-containing carbon compound.
Scheme 1. Substitution of 3-phenyl-1-propanol to 1-bromo-3-phenylpropane.
An Sn2 reaction occurred replacing OH with the Br halide at the primary carbon location.
Scheme 2. Substitution of 2-pentanol to form 2-bromopentane
Scheme 3. Substitution of 2,4,6-trimethylcyclohexanol to form…show more content… To prepare 3, Mixture made with 2.00g of alcoholic starting material and 5.00mL of Lucas reagent. The mixture is added to a 50mL round bottom flask and heated for 20 minutes in a warm water bath, then cooled in an ice bath. Once cooled, the mixture is transferred to a separatory funnel to be washed with two 10mL portions of water and once with a 1.5g (0.018mol) sodium bicarbonate and 30mL of water. This separated by density and the organic layer was on top. Once separated, the organic layer was dried with sodium sulfate. Product 3 was collected and weighed (1.015g, 0.0087 mol, 51%). 1H NMR, IR, and GC were collected to analyze the product. 1H NMR (CDCl3, 200 MHz) 0.906 (s, 3H), 0.996 (s,3H), 1.557 (n, 1H), 1.637 (d, 2H), 1.896 (d, 6H). IR (cm-1) 3404, 2960, 2873,570. GC (TCD) 3.1m (18%), 4m