CHEM2314 Lab 6

Williamson Ether Synthesis of Phenacetin Background: Synthesize phenacetin from acetaminophen (Tylenol) via a Williamson ether synthesis.The Williamson ether synthesis is one of the simplest methods used to make ethers. The reaction is named after Alexander Williamson, who discovered the reaction in 1850. In this reaction, an alkoxide anion reacts with an alkyl halide via a substitution reaction.                         RO-Na+   +   R` – X   →   R-O-R`   +   NaX Alkoxides are strong nucleophiles that tend to react via an SN2 mechanism. As a result, the reaction works best with primary alkyl halides. In a traditional Williamson ether synthesis, the alkoxide is generated by reacting sodium hydride (NaH) with an alcohol. ROH   +   NaH    →    RO-Na+   +   H2 While this reaction is very efficient, it does pose a fire hazard, as it is possible for hydrogen gas to ignite. In this lab, the alkoxide will be created using sodium hydroxide (NaOH). This is a much safer option, eliminating a…

The organic chemistry professor instructed students to synthesize 1-hexanethiol from 1-hexanol. Two students Sophie and Emily, disagreed on what reaction sequence to carry out in the lab. Emily's reaction sequence: 1-hexanol + NaSH --> 1-hexanethiol   Sophie's reaction sequence: 1-hexanol + 1. TsCl, 2. NaSH --> 1-hexanetiol Which is correct, Emily or Sophie?

Starting with cyclohexanone and ethanol as the only organic reagents, use any inorganic reagents to propose a synthesis for the target molecule.

Draw the structures of the two Aldol condensation products based on the identified aldehydes and ketones.

When 5-bromopentanal is treated with sodium borohydride, a compound is produced whose 13C NMR spectrum is shown here. In its IR spectrum, no absorption bands appear near 1700 cm-1 or above 3000 cm-1. Propose a mechanism to account for the formation of this product. NABH4 ? H. Br ETOH 200 150 100 50 Chemical shift (ppm) Fo

Which would be the best reagent to convert benzaldehyde to benzoic acid? O PCC KMnO4 NaBH4 OLIAIH4

5. Propose a mechanism for the base-catalyzed hydrolysis of the nitrile. H₂O NaOH CEN 6. Propose a mechanism for aldol reaction. HiM Н н NaOH H₂O

Please complete the Aldol condensation reactions shown below

Propose reagents and conditions for the following multistep syntheses. You may use any reagents necessary. Be sure to draw all isolable intermediates. Br. H.

An aldol addition can be catalyzed by acids as well as by bases. Propose a mechanism for the acid-catalyzed aldol addition of propanal.

Modify the given starting materials to give the mixed aldol product.

acetyl aldehyde produce 2-Butenal in basic solution through aldol condensation reaction. Select one: True False

HO Aldol reactions (condensation of two aldehydes or ketones to yield a ẞ-hydroxy carbonyl) can go in reverse (ẞ-hydroxy carbonyl to two aldehyde/ketones, a retro-aldol). Propose mechanisms for the following two transformations, using both intra-molecular aldol and a retro-aldol reactions. Be sure to follow the rules we have discussed for writing reaction mechanisms! Na OEt ethanol OH O

In an aldol condensation reaction, acetone and benzaldehyde are mixed in the presence of sodium hydroxide to produce dibenzalacetone.  Does it matter whether the acetone is added first to the aq. NaOH solution then the benzaldehyde, or if the benzaldehyde is added first to the aq. NaOH solution, then the acetone? Explain