Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
Difference between alcohol and phenol? |
In alcohols, the OH is bonded to a sp3 carbon. In phenols, the OH is bonded to a sp2 carbon in a aromatic ring. |
|
|
How can you form an alcohol from an alkyl group? (RX) What kind of reactions are these? |
![Add OH- (for primary [or 2*] RX, SN2 occurs).
Add H2O (for tertiary RX, SN1 occurs) [or 2*, where SN1 or SN2 occurs].](https://images.cram.com/images/upload-flashcards/76/88/49/10768849_m.png)
Add OH- (for primary [or 2*] RX, SN2 occurs). Add H2O (for tertiary RX, SN1 occurs) [or 2*, where SN1 or SN2 occurs]. |
|
|
How can you form an alcohol from an alkene? What types of alcohols can you form? What type of reactions and what rules apply? |
Acid catalysed addition of H2O. This forms 2* alcohols because of Markownikoffs rule. Add H+ followed by H2O. Hydroboration oxidation. This forms 1* alcohols because of Anti-Markownikoffs rule. Add B2H6 (or BH3) followed by OH- and H2O2. Note can use either reactions for symerical alkenes to form 1 product, eg but-2ene into but-2-ol. |
|
Name of reaction? What are the reagents? What are the products? What is the mechanism? |
Acid catalysed addition of H2O. 2* alcohols favoured! |
|
How to form primary alcohols, what reagents, name of reaction, mechanism? What is the electrophile and nucleophile? |
Hydroboration-oxidation. Nu = H- E= BH3 |
|
|
How to form an alcohol from an aldehyde? What type of alcohol is formed? |
use NaBH4 followed by water. primary alcohol. |
|
|
How to form alcohol from ketone? What type of alcohol is formed? |
Use NaBH4 followed by water. 2ndary alcohol. |
|
|
How to form an alcohol from ester? What type of alcohol formed? |
React with LiAlH4 (a stronger reducing agent) then followed by H3O+ or H2O. alcohol formed depends on the structure of the ester, just note you CANNOT form 3* alcohols. |
|
How to form alcohol from this? Reagents? Products? |
Note the acyl component (black one) CANNOT form tertiary alcohols, but the alkoxy component (blue) can. |
|
|
How do you form a grignard reaction? |
RX (alkyl halide) -> (Mg in dry ether) RMgX so, remember that Mg squeezes between the carbon and the halogen, and due to being electropositive will make the carbon electronegative (carbanion). |
|
|
What is an epoxide? |
also known as ethylene oxide. |
|
|
Grignard reagent + HCHO (methanal) -> |
1* alcohol with one more carbon |
|
Mechanism of Grignard reagent + HCHO. |
|
|
|
Grignard reagent + ethylene oxide (epoxide) -> |
1* alcohol with two more carbons |
|
reacted with HCHO, what are the reagents, and products. |
Primary alcohol + 1 more carbon. |
|
Reaction mechanism? |
|
|
Reacted with ethylene oxide (epoxide) what are the reagents, what are the products? |
Primary alcohol with two more carbons. |
|
|
Grignard reagent + aldehyde (other than methanal)? |
2* alcohol |
|
|
Grignard reagent + ketone? |
3* alcohol. |
|
|
Grignard reagent + ester or acyl chloride? |
3* alcohol (2 groups are the same) Just note, 2* alcohol for HCO2R or HCOX. ALSO REMEMBER 2 mol equivalent of the grignard. |
|
|
Alcohols are said to be aliphatic, what does this mean? Are phenols more acidic than alcohols? What does EWG and EDG do on phenol group? |
Because they can be both acidic and basic. Phenols are more acidic due to having delocalised electron and resonance stabilized form. Electron withdrawing group increases acidity. Electron donating group decreases acidity. |
|
|
Alcohols can react as a acid or base in certain conditions, what are these conditions and what are the products? |
In strong base (Na+NH2-) it acts as a acid, donating a proton forms alkoxide. In strong acid (H2SO4) it acts as a base and receives a proton forms oxonium ion. |
|
|
How to form ether from alcohol? |
1. Form alkoxide (addition of strong base Na+NH2-). 2. React alkoxide with alkyl halide. 3. ether forms + halogen ion. |
|
|
How to form alkyl halide from alcohols? |
1. Form oxonium ion (react with strong acid HCl). 2. React with nucleophile (overall HCl -> Cl-, the nucleophile). 3. Water forms and alkyl halide. |
|
For substitution reactions which alcohols proceed via SN1 or SN2 during adition of HCl? |
Tertiary alcohol = SN1 Primary alcohol = SN2 Secondary alcohol = SN1 or SN2 |
|
|
Substitution reaction of alcohol -> alkyl chloride. What about alkyl bromide? |
Add SOCl2 in pyridine, Cl substitutes OH. PBr3. |
|
|
Elimination reactions for alcohols, which is E2 and E1? |
Tertiary = E1 (carbocation!) Primary = E2 Secondary = E1 or E2 |
|
|
How to form aldehyde from alkene? |
Ozonolysis (O3 followed by Zn/H3O+). |
|
|
How to form ketone on benzene ring? |
Friedel crafts acylation of an aromatic ring. Benzene ring+ acyl chloride -> (AlCl3) ketone on benzene ring + HCl. |
|
|
How to form ONLY aldehyde from oxidation of alcohol? |
Use PCC as a reagent (mild oxidising agent). PRIMARY alcohol. |
|
|
How to form carboxylic acid from alcohol? |
add H2CrO4 -> aldehyde -> carboxylic acid. PRIMARY alcohol. |
|
|
How to form ketone from alcohol? |
add H2CrO4 to secondary alcohol. |
|
|
How to form alcohol from aldehyde/ketone? |
1. NaBH4 2. H2O aldehyde -> primary alcohol ketone -> secondary alcohol |
|
|
There are two possible types of nucleophilic addition to a ketone/aldehyde. What are they? |
Nu- attacks aldehyde/ketone (the carbonyl C=O) Aldehyde/ketone act as Nu (due to lone pairs on oxygen) in presence of acid (H+). |
|
mechanism? |
|
|
|
In nucleophilic addition, do which reacts faster between ketone vs aldehyde? why? |
Aldehyde fast (methanal fastest, only H bonded to carbonyl group). Ketone slowest. Because the more alkyl groups (R) bonded to carbonyl group increases steric hindrence (slower). Also ED inductive effect of alkyl groups causes Carbonyl carbon to be less positive, so less tendency of Nu- to attack it. |
|
How do you form this? |
Add cyanide (C-N), a nucleophile! Hydrolyse nitrile group to form carboxylic acid. |
|
|
Nucleophile addition of H2O to aldehyde/ketone? |
keto favors left. Aldehyde favors right. Forms diol! |
|
|
Nucleophile addition of an alcohol to aldehyde or ketone? |
react with 2 mol of alcohol in presence of acid catalyst to form acetal. 1 mol = hemiacetal. (alcohol is the nucleophile) |
|
|
Nucleophilic addition of amines to aldehyde/ketone? |
note h2o eliminated to form imine. |
|
How to form? Names? |
1. oxime 2. hydrazone R-NH2 react with aldehyde/ketone. R= OH or NH2. |
