CH312 – Chemistry – Flashcards

Epoxidation reactions are stereospecific; a trans double bond will give the trans epoxide; cis double bonds will give the cis epoxide.

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NaBH₄/CH₃OH will only reduce the carbonyl and will leave the double bond alone.

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H₂/Pd on C (1 equivalent) will reduce the double bond first.

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H₂/Pd on C (excess) will reduce the double bond first, and if you have enough, will reduce the ketone to an alcohol. 

NaBH₄/CH₃OH will not reduce the double bond no matter how much you have. H^- is a nucleophile and won't attack the double bond because it has high electron density.

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Amides may be synthesized from carboxylic acids provided that you include a "dehydrating agent" such as DCC (dicyclohexylcarbodiimide).

There are quite a few suitable starting materials since LAH is such a strong reducing agent. Benzaldehye as well as the following compounds would work.

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Acids + amines + DCC --> amides

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           Thermodynamic enol              kinetic enol

The more substituted double bond is the most stable. The kinetic enol is formed first, and at low temperatures. 

four carbon acid - butyric acid or butanoic acid

four carbon alcohol - butanol (butyl alcohol)

butyl butyrate (common) or butyl butanoate (IUPAC)

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The product is a mixed anhydride.

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The kinetic enolate (less substituted double bond) is formed under these reaction conditions, so alkylation takes place on the least substituted carbon.

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Formation of the thermodynamic enolate occurs under these reaction conditions (room temp, polar protic solvent). 

Yes - esters can be hydrolyzed under basic or acidic conditions.

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Amides may not be used to sythesize esters; all others (acids, acid chlorides, anhydrides) may. 

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Note: formic acid is HCO₂H

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Four - three to the right of the carbonyl carbon and one to the left.

They would both have a carbonyl stretch around 1700

cm^-1, but the carboxylic acid would also have a large, broad OH stretch around 3500 cm^-1.

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Anhydrides may be prepared by heating the heck out of acids if the acids are in close proximity.

Compound B (1,3-diketone) has the most acidic protons because the enolate is stabilized by several resonance forms.

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The order of reactivity is:

Acid Chlorides > Anhydrides > Esters, acids > Amides

This is an acid chloride so the suffix is "oyl chloride". It is a derivative of benzoic acid, so you drop  the "ic acid" and replace it with the appropriate suffix.

Benzoyl chloride

Friedel-Crafts acylation reactions require an acid chloride and AlCl₃ catalyst.

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This is a Friedel-Crafts alkylation and requires a haloalkane and aluminum chloride catalyst. This reaction works best if the carbocation that would result from the alkyl halide cannot rearrange - a simple alkyl halide like that above, or a tertiary alkyl halide. 

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Nitration of an aromatic ring is an electrophilic aromatic substitution reaction. Chloro and methy substituents are both ortho,para-directors, so the nitro group goes ortho and para to both groups. The isomer with the nitro group between the groups (ortho to both) will not form because of steric hindrance in a 1,2,3-trisubstituted benzene. 

Yes, it is planar, cyclic, fully conjugated and satisfies Huckel's rule (4n + 2 electrons, where n = 0).

Both compounds are aromatic, but the lone pair on nitrogen has a different role in each. In pyridine, the lone pair is orthogonal to the aromatic system and doesn't participate in the pi system. It is available for bonding. In pyrolle, the lone pair is part of the aromatic system. If it were to bond to a proton, that would disrupt the aromatic system.

1) planar

2) fully conjugated

3) cyclic

4) 4n+2 electrons (Huckel's Rule)

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intramolecular Friedel Crafts acylation reaction

Friedel-Crafts reactions go through a carbocation-like intermediate which will rearrange to give the most stable carbocations.

Stability:  Primary < secondary < tertiary

All meta directors are deactivating. They are substituents that have a partially positive atom bonded to the aromatic ring. All substituents with a carbonyl group (aldehydes, ketones, carboxylic acids), -NO₂, -SO₃H, -CN, are meta directors.

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A Grignard reagent will add twice to an acid chloride or an ester. The first step is a substutiton reaction that gives a ketone as a product; the next step is the reaction of that ketone with another Grignard reagent to give an addition product.

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Grignard reagents and organolithium reagents will add 1,2 to an a,b-unsaturated carbonyl (they add to the ketone). 

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An organocopper reagent will add 1,4 to an a,b-unsaturated carbonyl compound.

 This is an addition reaction - a new carbon-carbon bond is formed at the carbonyl, turning it into an alcohol and a new 2-carbon fragment is added. Grignard or organolithium reagents will do this, so the reagent can be either CH₃CH₂MgBr or CH₃CH₂Li

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LiAlH₄ (LAH) is a very strong reducing agent and will take ketones to alcohols, aldehydes to alcohols and amides to amines.

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NaBH4 (sodium borohydride) is a mild reducing agent and will reduce ketones and aldehydes to alcohols but not esters or acid chlorides.