4. Predict the products of the following irreversible additions to carboxylic acid derivatives. CI excess MeMgBr excess NaBH4 CI excess MeLi excess LiAlH4 CI CI NMe2 excess MeMgBr NMe2 excess NaBH4 NMe2 excess MeLi NMe2 excess LiAlH4

H₂C 0 NH₂ B₂, NaOH 98 H₂C OH When an a-hydroxy amide is treated with try in aqueous NaOH under Hofmann rearrangement conditions, loss of CO, occurs and a chain-shortened aldehyde is formed. The mechanhum involves the following steps: Base abstracts an acidic amide proton, yielding amide anion The amide anion reacts with bromine in an e-substitution reaction to give N-bromoamide 2. Abstraction of the remaining amide proton by base gives a resonance-stabilized bromoamide anion Rearangement occurs to yield isocyanate Water adds to the isocyanate to yield carbamic acid Elimination of CD, yields carbinolamine Following proton transfer, expubion of ammonia yields the final product aldehyde Write out the mechanism on a separate sheet of paper, and then draw the structures of carbamic acid 5 and isocyanate 4. H 400, ANH, You do not have to consider stereochemistry. You do not have to explicitly draw Hatoms De not include lone pairs in your answer. They will not be considered in the grading…

Identify the mechanism by which each of the reactions above proceeds from among the mechanisms listed. Use the letters a - i for your answers.

NOC XT Ph CH₂ Both primary and secondary amines add to a ß-unsaturated aldehydes and ketones to yield ß-amino aldehydes and ketones rather than the alternative imines. Under typical reaction conditions, both direct and conjugate modes of addition occur rapidly. But because the reactions are reversible, they generally proceed with thermodynamic control rather than kinetic control so the more stable conjugate addition product is often obtained to the complete exclusion of the less stable direct addition product. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions H H CH3NH₂ CH3 H-A :A Ph NHCH3 вон CH3 :A H-A 8b

Answer questions a-c about the Bronsted acid-base reaction below using the identifying letters A-D below each structure. The pKa's for the acids of interest are: ethylammonium ion (pK = 10.8), and hydrogen chloride (pKa = -7). CH3- NH2 CH3. NH3 cī H-CI H2 A в D chloride ethylamine hydrogen chloride ethylammonium a) The stronger acid is b) Its conjugate base is c) The species that predominate at equilibrium are (two letters, e.g. ac)

Fill in the missing structure(s) for the reaction pathways shown below. Provideall starting material(s), reagent(s), or product(s). If more than one product can beformed, draw all major products. If more than one starting material or reagent ispossible, write all starting materials or reagents. Include stereochemistry in youranswer, if applicable, and draw all stereoisomers.

Which of the following bases would be able to irreversibly deprotonate butanal? 1. NaOH 2. H2O 3. NaOCH3 4. More than one 5. None

Assign an E or Z configuration to these dicarboxylic acids, each of which is an intermedi- ate in the tricarboxylic acid cycle. Under each is its common name. H. COOH НООС, COOH (a) (Ь) C=C H CH,COOH HOOC H. Fumaric acid Aconitic acid

Based on the given information, need help with the following question. What are your two organolithium reagents A and E? Give a reason to support your answer.