Holot CH3 H3C Ph₂p-CHCH3 Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction. In the reaction, a triphenylphosphorine ylide, also called a phosphorane, adds to an aldehyde/ketone to give a four-membered cyclic intermediate called an oxaphosphetane. The oxaphosphetane is not isolated but instead spontaneously decomposes to release triphenylphosphine oxide and an alkene. L CXT CH3 H₂C Br-CH₂CH3 :PPh3 The ylide is formed by reaction of triphenylphosphine, a good nucleophile, with a primary alkyl halide in an SN2 reaction, followed by deprotonation of the carbon with a strong base, such as butyllithium. The carbonyl carbon and the carbon originally bonded to the halogen become the two carbons with the double bond in the product alkene CH3 The real value of the Wittig reaction lies in its ability to yield an alkene of predictable structure, as the C=C bond is precisely where the C-O bond was in the reactant and no isomers (other than E/Z isomers) are formed. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions Ph3P-CH₂CH3 Br Ph3P=O 76

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 an attempt to synthesize compound C through a two-step process, a chemist discovered after completing the first step that they had inadvertently produced two distinct compounds, A and B. Upon examining the infrared spectroscopy (IR) results, it was observed that both A and B exhibited peaks indicative of a ketone and an ester group. Please provide the molecular structures of A and B. OEt NaOEt ΕΙΟ A B In a chemical experiment, they noticed that both components, A and B, from a combined sample turned into a new compound, C, during the following stage. The task is to determine what compound C looks like and explain how compound A or B changes into compound C through a reaction. Compound C should be the primary molecule containing carbon created in this process, not just a by-product. A B H3O+, H₂O, A Mechanism = с

the organic compound 2-heptanone, belonging to the ketone family, is responsible for the strong penetrating odor in Roquefort cheeses. Starting from acetylene as the starting reagent, propose a synthesis line with the reaction mechanisms involved for the synthetic obtaining of 2-heptanone and use it as a food additive in analogous cheeses.

Give the major organic product for each of the reactions

H NH₂ ཡིནྣཾ ༥ ཨ ཨནྡྷ༥ ༠ ཨི་ཝཱ, ཙ ཨ་ར༩ H NH3+ the acidity of the amine ion drives the reaction to shift toward the conjugate base of the carboxylic acid product. the resulting carboxylic acid ion is a weaker base than an acetate ion. O aldehydes are more reactive toward nucleophiles than ketones. Onucleophilic attack occurs preferentially at the less hindered carbon of the formyl group.

Give an example of an ester that is used to activate alcohols towards nucleophilic substitution and beta-elimination reactions

This is the structure of xylan given, is the mechanism still the same (would there be two hydrolysis steps)?