H3C OH 1. Br₂, PBг3 2. H₂O H3C OH Br The a-bromination of carbonyl compounds by Br₂ in acetic acid is limited to aldehydes and ketones because acids, esters, and amides don't enolize to a sufficient extent. Carboxylic acids, however, can be a-brominated by first converting the carboxylic acid to an acid bromide by treatment with PBr3. Following enolization of the acid bromide, Br₂ reacts in an a-substitution reaction. Hydrolysis of the acid bromide completes the reaction. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions 20 H₂C C+XT Br OH Br 20 Br 36 P-Br Br H₂C Br

Draw the principal organic product for the reaction of 2-bromohexane with lithium in diethyl ether, followed by formaldehyde in diethyl ether, and then followed by dilute acid. Click and drag to start drawing a structure. X A G P

POST-LABORATORY QUESTIONS 1. Effective mosquito repellents contain DEET (N,N-diethyl-3-methylbenzamide). If you were to synthesize this compound, with what carboxylic acid and amine would you start? Draw their structures. CH3 DEET O C-N CH₂CH3 CH₂CH3 H3C Metadone 2. Metadone, a narcotic analgesic (shown below as the amine), is dispensed as its hydrochloride salt. Explain the use of the salt rather than the amine. Use the structure shown and convert it to the hydrochloride salt. N-CH3 ogged

Q: What ester results in the following reflux? pentanoic acid CH₂CH₂OH OH R' R-OH Q: What alcohol and acid must we use to make the following ester? O O H+ OH H+ benzyl isobutanoate H₂O

1. NaOEt CO₂Et 2. H3O+ 3. heat Br H3C H₁C CO₂Et CO₂H CO2 + EtOH The malonic ester synthesis is a carbonyl alkylation reaction. It is used to prepare carboxylic acids from primary alkyl halides, lengthening the carbon chain by two atoms. Thus, the product can be visualized as being a "substituted acetic acid." The reaction consists of three steps: generation of the enolate anion followed by SN2 reaction with a primary alkyl halide, ester hydrolysis under acid conditions, and decarboxylation. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions EtO₂C X ¯:0: :0: Br: EtO₂C. Br CH3 H3C CH3 CH3 56

Ketones and aldehydes react with sodium acetylide (the sodium salt of acetylene) to give alcohols, as shown in the following example: R OH 1. HC=C: Na* 2. H30* R2 Rí `R2 HC Draw the structure of the major reaction product when the following compound reacts with sodium acetylide, assuming that the reaction takes preferentially from the Re face of the carbonyl group. • Use the wedge/hash bond tools to indicate stereochemistry where it exists. • You do not have to explicitly draw H atoms. • If a group is achiral, do not use wedged or hashed bonds on it. H H3C H CH3

Benzene can be hydroxylated by treating it with hydrogen peroxide and a strong acid such as trifluoromethanesulfonic acid (TfOH). Propose amechanism for this reaction

Give the systematic (IUPAC) names for these molecules. Boononon cnolonongron. НаСНз CHОССH2СH2СНCHЗ CH3 phenyl propanoate |4-methyl pentane methanoat Incorrect. You mixed up the acyl and alkoxy portions of the molecule. Name the alkoxy part first, followed by the acyl part.

In biochemical reactions, decarboxylation of carboxylic acids typically takes place for-keto carboxylic acids. Justify a rational why nature opted for-keto carboxylic acid decarboxylation. Among the following types of biochemical reactions, ester hydrolysis, rearrangement reactions, water elimination reactions, and anhydride hydrolyses, which one is the most favorable one. Rank the above reactions types in the order of being the most to least favorable reaction

Draw the structures of the products from the hydrolysis of each of the following with NaOHNaOH.